DEV Community: IPv4 tradehub

How to Actually Calculate How Much IP Address Space Your Company Will Need Next Year

IPv4 tradehub — Mon, 21 Sep 2026 11:33:24 +0000

Most companies are running out of IP addresses because they grow exponentially. They wrongly estimate the number of end devices that will be connected to the network. Someone says “about 500 addresses” and no one bothers to check, while in the same quarter a new office opens, a cloud project launches and a ton of IoT devices appear. Suddenly the network team has to rush to get a new block of IPs since IPv4 addresses are not the cheapest thing to purchase in bulk.
Luckily, there is no need to guess the required number of IPs. A simple 5-step method helps to calculate it.

Step 1: Count What You Use Today

Start with the inventory. Take a look at all the IPs your company is using right now:
• Servers and virtual machines
• Your employees' personal devices
• Printers, cameras and other equipment
• Public services (websites, mail servers, VPN gateways)
• Cloud and hosting platforms
• Customer addresses, for ISPs or hosting companies
IP addresses should be pulled from your IPAM tool, DHCP servers or network sweeps. Forget about the spreadsheet you saved last year, it's most likely out of date.

Step 2: Separate "Assigned" from "Actually Used"

Many companies have addresses that nobody is using. Old test servers, retired devices and forgotten subnets.
Record two numbers. How many addresses are assigned and how many are actually being used. The difference between these two numbers is space you may be able to reclaim before having to buy anything new.

Step 3: Estimate Your Growth

This is the section that people tend to overlook. I want you to consider three aspects and express them as a percentage:
• Growth: What has been the growth of your address base during the past 12 months? For instance, have you added 1000 new addresses per year or 200?
• Plans: Will you be launching new products/offices this year? Are there any plans for expansion or acquisition of new customers in your address book?
• Technology: Are you embracing more remote employees, cloud-based software, and IoT-enabled devices?

Step 4: Add a Safety Buffer

**Never plan on designing for exactly what you think you'll need. Always budget an additional 10-20% for things like unexpected projects or new customers who need a chunk of address space allocated to them.
You also have to consider subnetting waste where addresses are lost to network and broadcast addresses and when you divide a subnet into smaller subnets of different sizes, there will always be some addresses left over that can't be used. Another 10-15% is a good rule of thumb to use.

Step 5: Round Up to a Real Block Size

IP space comes in fixed sizes, so your final number must match one. Here are the common ones:
Block Total Addresses
/24 256
/23 512
/22 1,024
/21 2,048
/20 4,096

A Quick Example

Let's say your company uses 1,200 addresses today.
• Expected growth (20%): +240, so 1,440
• Safety buffer (15%): +216, so about 1,656
• Nearest block that fits: a /21 (2,048 addresses)
A /22 would have felt like enough, but it would have run out in months. This is exactly why rounding matters.

Don't Forget This: Regulators May Ask You to Prove It

If your plan is to acquire space via RIR transfer, then the registry will most likely require a justification for the need of the resources and that need should be for some period of time, often 12-24 months as a rough estimate (but it varies) based on the registry and something concrete like the calculation above will definitely make the process a lot easier compared to just throwing darts at the wall and hoping for the best.

Common Mistakes to Avoid

• Only considering devices, and not servers, gateways and infrastructure
• Ignoring NAT and cloud use that quietly eats up public addresses
• Planning for one year, but buying for exactly one year, with no buffer
• Never auditing old subnets to look for space

How to Spot a Fake or Fraudulent IPv4 Seller Before You Lose Money

IPv4 tradehub — Mon, 21 Sep 2026 11:18:57 +0000

Imagine paying $30,000 for a block of IP addresses, only to find out the seller never owned them.
Your money is gone, the seller has vanished and your network is still stuck. That scenario occurs far too often these days. IPv4 address blocks are becoming a scarce resource. Scammers are taking advantage of this. Here's what you should do if you are purchasing IPv4 space.

Why IPv4 Scams Are Growing

The world has run out of new IPv4 addresses years ago, and today, the only source of obtaining them is through purchase means from an existing owner. This has led to the creation of a competitive secondary market. Naturally, where there is such demand and profit, scammers emerge, offering both fraudulent and blacklisted IP addresses for sale. Some dishonest vendors even lease out the same numerical IP address to multiple clients, while others offer hijacked or blacklisted IPs.

Red Flags to Watch For

• The price is too good to be true: If a seller offers a price significantly below the market value, it is necessary to take this information with a grain of salt. A high discount on a desirable IPv4 block is a clear indication that the owner is not in the position to make this deal.
• Seller does not want to provide any proof of ownership: Any owner of an IPv4 block with a history can provide the necessary documentation so that the buyer can verify the details of the block. Representatives of scams will try to avoid providing this information.
• Seller does not want to go through the official procedure of the transfer: An official sale of a block of IP addresses should be made with the approval of a registry of a particular region (RIR). If the seller says that it is not necessary to turn to them, this serves as another indicator of scam.
• Seller is pressuring the client to complete the deal as soon as possible: Scammers often use such phrases as “another buyer is waiting” and provide other examples of urgency. It should be noted that real estate transactions of this type do not require haste.
• Seller offers to complete the transaction only in certain payments: If the scammer offers to pay a large sum in Bitcoin or any other cryptocurrency or a non-traceable transfer, this is a suspicious method.
• Seller does not have a legitimate business: One of the signs of a scam is a new company that does not have any reviews and is not registered in all regions. A reliable company will have a website where you can track the necessary details of the transaction.

How to Verify a Seller Step by Step

Check the registry records: look up the IP block in question in the WHOIS database of the relevant RIR to make sure that the organization name matches that of the seller.
Use a registered broker: several registries maintain a list of approved brokers and making a purchase through them significantly reduces the risk of an IP address theft.
Ask for documentation: **request the company's registration papers and authorization to resell the IP addresses and ensure that the details match the information provided by the seller.
**Check the reputation of the block: run a blacklist check on all of the IP addresses you are planning to acquire to ensure that the seller does not have a history of scams.
Check the routing history: verify the block's routing history to ensure that it was not hijacked in the past.
Use escrow and a contract: opt for an escrow service to make sure that the payment is only transferred to the seller after the buyer receives the IP address. The contract should state all of the conditions of the deal and outline the terms of the transfer and cancellation in case of fraud.

A Quick Pre-Purchase Checklist

• Seller is identified, his company is verified
• Ownership is registered
• Block is checked for blacklists and routing problems
• Transfer will be approved by the RIR
• Escrow and a written contract are in place
• Price is in the normal range
If any of these points are missing, you should stop the deal.

What Is IP Leasing and How Does It Actually Work?

IPv4 tradehub — Fri, 18 Sep 2026 12:03:29 +0000

Imagine having your own intellectual property (IP), a creation of your mind that you have spent a lot of time perfecting and can sell for a good price. However, instead of selling your creation, you lease it to other companies allowing them to use it under your rules while you collect a steady income. IP leasing is one of the latest trends in the corporate world that can make you a lot of money if done right.

Read this if you are: a star upstart with a great brand name or patent, a large company that wants to diversify its sources of income and you have no idea how to do that other than develop new products or a business owner that is curious about how companies such as Disney or Nike make money without producing anything themselves.

So, What Exactly Is IP Leasing?

IP leasing is when you allow another company to use your intellectual property, such as a trademark, patent, copyright, or trade secret, for a certain amount of time in exchange for a royalty or licensing fee. The intellectual property is not sold, only leased or licensed for a specific period of time and under specific conditions.
Think of IP leasing as renting your idea or creation. You do not sell your creation, but you allow someone else to use it for a certain amount of time and in exchange for a fee, similar to how you might rent an apartment.

How It Actually Works

Ownership retention: The property rights of the asset stay with the assignor (licensor).
Licensing agreement: A formal contract is drawn up that determines the rights given to the recipient (licensee). It should state what can and cannot be used, where and for how long the usage is allowed.
Payment conditions: The payment method should be specified in the contract as a fixed sum, a percentage of sales (royalty) or a combination of both.
The use of intellectual property: The licensee may apply the asset for example, by putting a trademark on a product, implementing a patent in the production process, or operating a business under a franchising system.
Monitoring: The licensor should watch over the use of their asset to ensure that the terms of the contract are followed and the company’s reputation is not at risk.

Why Companies Do This

• Extra income with little effort: You don't have to create or promote anything.
• Global reach with no global staff: You can let other companies handle the business in regions you're not in.
• Shared risk and reward: Someone else takes over the creation and local risk, but you still get a cut.
• Brand building: Think of all the different ways Disney's characters appear, from lunchboxes to clothing to theme parks around the world, yet Disney doesn't produce all of that itself.

The Hidden Asset Sitting in Your Network: Unused IPv4 Space

IPv4 tradehub — Fri, 18 Sep 2026 11:37:40 +0000

Quick question: Do you know precisely how many IP addresses your organization owns right now?
Most IT departments can’t say and the potential upside for unused and unmonitored IP space could be significant.

The Overlooked Asset

IPv4 addresses have been depleted years ago. There is no new supply coming on the scene. Whatever is on the market now is the total amount of existing inventory. This scarcity has transformed a once cheap and abundant resource into a true market asset that appreciates in value over time, similar to real-estate.
So if you're business is sitting on inventory that it cannot consume, it's actually not dead weight. It's equity.

Where This Space Usually Hides

Unused IPv4 blocks are not obvious. They can accumulate for various reasons, e.g.
• Old infrastructure decommissioned but not formally returned
• Oversized subnets allocated with the expectation of future expansion that were curtailed
• Consolidations through mergers and acquisitions resulted in overlapping allocations
• Simple lack of ownership of the audit process
None of these scenarios present an obvious alert on a dashboard, but represent valuable, under-utilized assets that are currently unmonitored and unmonetized.

Why This Matters Right Now

Two facts are true at the same time:

Demand for IPv4 space keeps increasing as the cloud, hosting and network infrastructure keep growing
Supply is permanently fixed, it can only be moved within companies, not increased That combination is what makes that the option to lease or sell unused IPv4 space has become a source of revenue for companies who want to take the time to check what they're holding.

What to Do About It

Even if you have a small project to evaluate your performance, there are only three things to do:
• Do an audit of all your allocations: compare what you have with what is used
• Highlight all the idling resources: decommissioned systems, old subnets or clusters
• Have it all verified and ready to market as soon as possible: buyers and lessors want clean and well-organized IP space

Your ISP Is One Bad IP Decision Away From a Very Expensive Weekend

IPv4 tradehub — Thu, 17 Sep 2026 11:04:41 +0000

Imagine: its 2 a.m. Your NOC team is tearing out their hair. A customer's subnet has been blackholed by the peering ISP because you acquired a block that had a murky ownership trail and now you're in a pissing match with a Regional Internet Registry while your uptime SLA goes down the toilet.
This scenario is becoming distressingly common as IPv4 has started to become a scarce resource. IPv4 RIR transfers are now one of the highest risk transactions for an ISP or data center operator to perform, and downtime incidents stemming from RIR transfer mistakes are now among the most common causes of network disruptions. There are a handful of simple, easily avoidable mistakes that, taken together, account for the majority of RIR transfer mishaps.

What an RIR Transfer Is

An RIR transfer refers to the redistribution of IP address resources, typically IPv4, from one entity to another, which requires the approval of one of the five regional internet registries (RIRs). While purchasing an IP address space is a common practice, it cannot be done offhand. First of all, one has to determine whether the RIR will authorize the transfer based on the needs of the buyer and the availability of the resource on the part of the seller.

Why It Matters Now

All five RIRs have exhausted their free pools and the growing number of ISPs are now relying on the transfer market rather than direct allocations. IPv4 addresses have become a true tradable commodity and the risks of acquiring legacy blocks are significant, as are the challenges posed by the fraudulent or double-sales. ISPs that acquire such resources may find themselves in routing disputes with peers and/or the RIR and/or delisted due to such activity or the RIR repossessing the block in question.

The Process, Step by Step

Verify eligibility: You will usually need an active ASN, a justified utilization plan and registration with the RIR in your region.
Check the seller: Ensure that they are the legal owner in WHOIS, free of any liens, holds, or that the block itself is not blacklisted; you inherit the reputation of the block.
A broker/lawyer is advisable to handle escrow: Draft a transfer agreement that will not be rejected by the RIR, and avoid litigation; skipping this step to save a fee is how transfers turn into lawsuits.
Submit to the RIR: Both parties sign and submit a signed agreement plus their registration and identity documents for processing, which takes weeks or months.
**Update routing information before cutover: **to prevent RPKI route leaks and invalid prefix announcements, notify upstream and perform an overlap during the migration, not a cutover.
Monitor announcements closely for 30–90 days since this is when the most dangerous period is: lingering blacklisted entries and routing anomalies from the previous holder could appear.

Where Downtime Comes From

Nearly every transfer outage is caused by the same few culprits: lack of legal validation (the block is reclaimed mid-transfer), absence of an RPKI update (upstream are filtering the announcement), no transition overlap (customers are cut during transition), ignored reputation history (immediate blacklisting) or underestimated processing time (capacity is planned based on space that has not been cleared).

How a growing ISP solved its IP Shortage without a Big Upfront Cost

IPv4 tradehub — Thu, 17 Sep 2026 10:42:00 +0000

One quarter of explosive growth. One frozen expansion plan. Here's how a mid-size ISP got unstuck without draining its budget.
Six months ago, one regional ISP was growing faster than their ability to add new customers. Lucky problem to have, except it wasn't. Each new sign up needed IP addresses and their pool was dangerously low. Expansion plans were frozen. Not from a lack of demand, but from addresses.
This is their story and the exact decision that got them growing again.

The Wall They Hit

The ISP has seen steady growth of their network over years on the back of a modest IPv4 allocation, but it is rapidly approaching the limits of its capacity. Now that growth trajectory is accelerating, fueled by surging residential contracts and a few small business clients, while the ISP has expanded its network presence into a neighboring region. The math doesn't add up anymore. Their engineering team has been cycling through addresses at an unprecedented rate; the problem is already manifest in their operations.
The solution of buying another block entirely was the obvious choice, but it also represented the expensive alternative. The purchase of a significant IPv4 block would require a large capital expenditure for the ISP, representing a risk factor to their ongoing investment in equipment, personnel and further expansion of their network.

The Real Problem Wasn't the Addresses It Was the Capital

This is the part that gets missed. The ISP didn't have an addressing problem. They had a cash-flow problem wearing an addressing costume. Buying outright would have solved the shortage and created a new one less money for the hardware and staff needed to actually serve the customers those addresses were for.

The Decision: Lease Instead of Buy

Instead of a large one-time purchase, they leased the IPv4 space they needed. Here's what changed immediately:
• No initial expenditures: since the budget that would have been allocated to address purchases could be redirected towards servers and network equipment.
• Reputation-Checked Infrastructure: The company did not inherit any undesirable reputation leftovers from the previous tenant and thus avoided additional expenditures on delisting and blacklisting cleansing.
• Scalability: In case of any growth projections, the company could simply amend the leased block size rather than committing to a larger purchase coldly estimated at the begging.

The Result

Within weeks, provisioning had returned to normal. New customers stopped waiting. The expansion in the new region, which had been frozen, resumed on schedule. And the capital that would have been tied up in an IPv4 purchase went directly into the infrastructure that makes a network grow, namely, servers, staff and service quality.

5 Signs Your Company Needs More IP Address Space And How to Get It Without Tying Up Capital

IPv4 tradehub — Tue, 15 Sep 2026 13:18:57 +0000

Most companies don't realize when a particular Tuesday rolls around that it's the day they will need to buy more IP address space. They've seen the signs for months and ignored them all.
The reality is, the majority of companies have already tied up capital in more IP address space than they possibly need. That doesn't mean the issue was hidden. It means no one was looking.
If you're an ISP, a hosting company or any kind of networking company, here are the five issues you should be able to recognize before they become an emergency.

You are reusing/recycling IPs faster than usual: If your team is spending more and more time wrangling the (re)assignment, reclaiming or “stretching” IP blocks than before, that’s a sure sign of shortage and growing companies seldom realize this in time as the transition into a “new normal” is gradual.

**New customer/server onboarding delays are becoming frequent: **Ask your network team if provisioning time has become slower in the last months or so. New customer onboarding or server provisioning taking longer by days because the team needs to “first get the addressing out of the way” is another sign of an impending IP address crisis.

**You're becoming more reliant on NAT: **While NAT is an enabler for many organizations, the fact that you're using it more often than you should be, is an issue. Each time you add in a new host to be masqueraded, you stretch out your IP addressing resource.

Your 12-month growth plan already assumes that the addressing will be somehow resolved: Not many organizations realize just how much they'll wish they had more IP space at such crucial moments. If addressing is not a priority in your 12 month plan, it's a safe bet to say that you'll end up in a bind trying to do something about it.

You simply haven't done an inventory audit of the current utilization: The fact that many businesses don't know how much room they have to grow is in itself a myth. Companies are unaware of just what incredible amount of information that they have at their disposal, and the truth is, that no one knows how much space they have until they decide to want to know.

So what do you actually do about it?

Here's where most companies assume the only fix is a big upfront purchase. It isn't.

Leasing IPv4 space is the move companies overlook. Rather than tying up cash in a large, one-time purchase, you gain access to valuable, thoroughly vetted address space today while preserving liquidity for other business needs. Servers, recruiting, marketing whatever you need to scale your operation, you can acquire without further financial commitment.
It's the same model enterprises use to great effect with office space, equipment, infrastructure and more. No one buys a data center on day one. They rent what they need to grow their business and then scale accordingly.

The real takeaway

Running out of IP address space is not something companies realize all of a sudden. It is a slow bleed that they do not necessarily notice before their business suffers from lost opportunities, project delays, or implementation issues. The solution is simple. It is common, but not actively sought after.

If any of the five symptoms sound familiar, then it is probably time to take measures.

The Global IPv4 Shortage And Why Your Business Might Already Be Part of the Solution

IPv4 tradehub — Tue, 15 Sep 2026 12:29:52 +0000

Somewhere in your network closet, you have an asset with a value you'd be surprised about. Not a server, not a piece of software, just a number, an IP address. And today, businesses are buying, selling and leasing them around the world.

Here's the twist: the world already ran out.

How We Got Here
IPv4 was initially designed to address the vast need of 4.3 billion addresses. Its significance and demand seemed to be limitless before smartphones, cloud-based servers and other devices came to dominate the modern world. As of now, all regional registries that allocate IPv4 addresses have exhausted their resources. Consequently, no new addresses will be available for allocation in the future.

Scarcity Created a Market

That shortage didn't just create a problem, it created an economy:
• Rising prices: IPv4 blocks are rising in value and behaving more like appreciating assets
• Leasing prevalence: Companies are able to lease the address space they need, rather than making large capital expenditures
• Address hoarding unveiled: Many companies are sitting on address blocks that they have forgotten about
This begs the question, do you know how much IPv4 address space your company owns that it is not currently using?

Hidden Value, Hiding in Plain Sight

Unused blocks usually come from the same few places:
• Old infrastructure that nobody decommissioned correctly
• Subnets, which were sized for some growth plan that changed
• Leftover space from some merger/acquisition
If that's you, then in fact you're sitting on cash, not dead weight.

Two Sides of the Same Shortage

• Have an excess space? You can rent it out and benefit from the unused assets.
• Need a larger space? You can rent in without any capital investment and without a long wait period.
The shortage did not close the door. It opened the market and it has started to pick winners. The only risk is that you don't know which side you are on.

Running Out of IPv4? Here's What Actually Happens Next

IPv4 tradehub — Mon, 14 Sep 2026 13:17:16 +0000

The free pool is gone, the waiting list takes over a year and the secondary market sets the price. Here's what that means for hosting and ISP businesses. IPv4 exhaustion is no longer a future risk that hosting providers and ISPs will have to address, it is the industry reality today, as all regional internet registries have exhausted their free pools and there is no longer a supply available. The only ways to get addresses are the official waiting lists, which are slow and unpredictable or the secondary market, where prices and availability fluctuate weekly.

For any business that depends on public IPv4 addresses to be able to onboard customers or scale infrastructure, understanding what happens at zero and what it costs to avoid getting there has become a core planning requirement, not a technical footnote.
The Data behind the Shortage

The numbers make the scale of the problem clear:

• ARIN's waiting list is now over a year deep: As of April 2026, the oldest unfulfilled request was being waited around 388 days, and 523 requests had remained unmet even after recent distributions. ARIN's own guidance put realistic waiting periods at 12-20 months and its free pool had been empty since 2015.
• The secondary market is busier than ever: Roughly 24 million IPv4 addresses had changed hands globally in only first five months of 2026, already more than half of all of 2025's full year total and at the fastest transfer pace ever recorded.
• Prices remain volatile and demand driven: Current market data put outright purchase prices in a range of $18 to $50 per address, depending on block size and registry region, with smaller blocks commanding a premium. Leasing runs roughly $0.30 to $0.60 per address per month.
• IPv6 adoption remains insufficient to bridge the gap: With global IPv6 adoption sitting at approximately 40%, a majority of internet facing infrastructure still requires IPv4 to be reachable.
Together, these numbers point to one conclusion: waiting until you're out of addresses is the most expensive and least reliable way to solve this problem.

What Actually Breaks When You Run Out

New customer onboarding is stalled: Sales can secure the deal but provisioning cannot assign an IP that does not exist. Every deployment waiting in the queue is a direct loss of revenue.
Existing customers are also impacted: Workarounds like reclaiming addresses from inactive accounts, shifting customers to shared or NAT-based IPv4 addresses and rationing new allocations address the immediate shortfall but impact use-cases that genuinely require dedicated IPs like mail-servers and certain compliance-bound workloads.
Reactive buying has higher cost and risk: Businesses that have to buy under time-pressure lose out on their negotiating leverage and are more likely to buy address blocks with unresolved reputation issues (previously flagged by spam filters or blacklisted) that takes months to remediate before they can be put to use.
Retention is at risk: With low switching costs in hosting and ISP markets, inability to provide requested IP-resources for a new deployment, a scaling-event or a compliance requirement provides customers with an opening to look elsewhere.

How to Stay Ahead of It

Providers who avoid this problem treat IPv4 inventory as an ongoing planning function rather than a reactive purchase:
• Audit current IP holdings on a fixed schedule, versus only acting when a shortage becomes apparent
• Forecast demand not against current demand, but against actual growth plans
• Buy blocks of IPv4 space before utilization gets tight, while there is still room to negotiate price, and to qualify the block
• Pursue a dual stack IPv6 rollout to minimize long term IPv4 dependence, while realizing that it won't satisfy immediate need
• Work with an established IPv4 partner, who can provide verifiable clean history, and who can quickly respond to critical timing needs

What Is an ASN (Autonomous System Number) and Does Your Company Need One?

IPv4 tradehub — Mon, 14 Sep 2026 11:27:00 +0000

If your own business has its own network infrastructure, multiple internet connections, or is moving to colocation or cloud environments, you may have encountered the term ASN. It's a technical-sounding term for good reason, but understanding it and whether it applies to you and your business will save you time, money and headaches when it comes to network redundancy, reliability and reach.

What Is an ASN?

An Autonomous System Number (ASN) is a numerical identifier for a particular network (or set of networks) on the Internet that are run under a common routing policy. In other words, the Internet is a collection of networks, each of which is considered an autonomous system (AS) and needs to have a unique number so all the routers in the world can find it.
Autonomous System Numbers are used in the Border Gateway Protocol (BGP), which is the standard for defining how traffic moves between networks on the Internet. Having your own ASN means you can advertise (announce) your IPs to the rest of the Internet and control how traffic is permitted in and out of your network, rather than relying only on the BGP of your upstream provider.

ASNs come in two basic types:

• Public ASNs: A publicly visible number assigned by a regional internet registry (RIR) such as ARIN (North America), RIPE NCC (Europe), APNIC (Asia-Pacific), LACNIC (Latin America) or AFRINIC (Africa). These are used for networks with their own routing policy connected to the public Internet.

• Private ASNs: Used internally by a network or between a company and a single service provider not visible on the global Internet.
The original range for ASN values was 1 to 65,535 (16-bit ASNs). These numbers were insufficient to meet the global demand and 32-bit ASNs were adopted, allowing a much larger pool of unique values (up to 4 billion).

How Does an ASN Work?

Most large routers on the Internet need to know how they can reach every other network. Rather than looking at every individual IP address, routers use ASNs to group blocks of IP addresses together and select where traffic going to those IPs should be directed.

Here's what happens when your organization has its own ASN:

You are allocated one or more blocks of IP space (or bring your own).
You announce ("advertise") those IPs to the Internet using BGP.
Other networks and Internet service providers see your ASN and send the appropriate traffic your way.
You control your own traffic routing policy - which providers carry your traffic and how. This is different than a traditional business Internet connection where your ISP does all your traffic routing on your behalf.

Who Needs an ASN?

Most businesses don't need an ASN in fact many small and medium businesses operate fine by not having them and allowing their IPs and routing policies to be managed by their Internet Service Provider. The main reason to acquire an ASN or the motivation, for some businesses would be if they were in one of the following categories.

Multihomed (Have Connections with More Than One ISP)
If your company has more than one Internet connection because you want to have redundancy (should one ISP fail, you'll still have Internet connectivity), you need an ASN and an independent IP address space because failover with standard BGP doesn't work. In other words, you can't "fail over" from one provider to another without an independent numbering scheme.
Want Full Control Over IP Address Space
A company would want an ASN if they needed to make their own IPs (their own addresses) portable. That is, they want to be able to change ISPs without renumbering their entire infrastructure, which would typically require returning the IPs they had with their former ISP.
Run a Data Center, Hosting Company or Cloud Service
These kinds of businesses host or resell hosting services to other businesses and therefore need their own ASN to manage and route large blocks of IPs independent from a single provider.
Peering Directly With Other Networks
Large companies, ISPs and content providers sometimes peer directly with each other to avoid routing traffic through other networks, which reduces latency. This requires an ASN.
Want Improved Network Performance / Redundancy
A company that owns an ASN can optimize the way in which they receive and send traffic out on their network, which can help with latency-sensitive applications, large SaaS providers or companies with a very international audience.

When You Don't Need an ASN:

Your company has a single Internet connection provider (ISP).
You don't manage your own public-facing IP address ranges.
Your infrastructure is mostly in the cloud (AWS, AZURE, Google Cloud etc.) and uses their networking software rather than your own advertised IP space.
Redundancy is handled at the application level rather than using multihomed routing.
For most companies, however, the overhead associated with an ASN far outweighs the benefits unless they're in one of the categories above.

How to Get an ASN

If your organization decides they need one, the general steps are as follows:

Determine eligibility, most RIRs require that you have a network that will connect to multiple external networks (multihoming).
Apply with the appropriate Regional Internet Registry (ARIN, RIPE NCC, APNIC, LACNIC or AFRINIC) based on your geographic location.
Get IP address space from the RIR or from an upstream provider that you will advertise under your ASN.
Configure BGP with your ISPs to start advertising your routes.
Maintain your registration with the RIR, including any fees and updates to routing information or contact info.

ASN Takeaway

An ASN is a basic building block of the Internet and a way to tell networks apart, allowing them to control how they're routed on the Internet. For most small businesses, which typically only have a single ISP connection, it's not a necessity. On the other hand, companies that are multihomed, want full control of their IP address space, need to peer directly with other networks or are running hosting/cloud infrastructure would benefit from having their own ASN. It's worth speaking with a network engineer and/or your ISP to see if it's a good fit based on the growth and needs of your business.