If you're self-employed, the AI services you pay for to do your work are generally deductible as business expenses. They usually go into a category such as internet and software services or bank and service fees, and if you also use the same account personally, the standard approach is to deduct only the share used for business. Once you actually start keeping the books, though, questions pile up: which category is right, and is a monthly subscription treated differently from pay-as-you-go API usage? This article lays out a practical way to handle these expenses, including how to document the business-use percentage. Tax rules vary by country, so confirm the final call with your local tax authority or an accountant.
Which expense category to use for AI subscriptions
Start with the basic premise: there is usually no single legally mandated category. Expense categories exist so you can see what your costs are made of, so what matters most is choosing one that fits what the expense actually is, and then sticking with it year after year. Filing the same subscription as "communications" one year and "miscellaneous" the next is worse for your records than either choice on its own.
A monthly subscription like ChatGPT fits naturally under internet or software services, on the reasoning that it's a service used over the internet, the same as cloud accounting software or web hosting. Many people file it under service fees instead, and both are commonly accepted in practice. Here is one way to organize the main AI-related costs:
| Expense | Example category | Notes |
|---|---|---|
| Monthly subscriptions like ChatGPT | Internet/software services (service fees also OK) | Split by business-use share if also used personally |
| Pay-as-you-go API usage | Internet/software services (service fees also OK) | Convert foreign-currency charges at time of payment |
| AI-related courses | Training/professional development | Be able to explain the link to your business |
| AI-related books | Books and publications | Same for e-books bought for research |
| Equipment such as a memory upgrade | Supplies | Items above your country's threshold are usually depreciated |
These categories are just examples. When in doubt, map the expense to the existing category in your books that's closest in nature, and keep using the same rule in later years. That alone removes most of the agonizing. The one thing to avoid is dumping every uncertain expense into "miscellaneous." A bloated miscellaneous line hides what you actually spent money on, makes life harder for you later, and takes more effort to explain if anyone asks.
How to split AI tools you also use personally
Splitting mixed-use expenses means deducting only the business share of something that serves both your work and your personal life. It's the same idea most freelancers already apply to a home office, rent or utilities, and it carries over directly to AI subscriptions. If one account handles both work research and dinner recipe ideas, deducting the full amount is hard to justify.
There's usually no fixed formula for the percentage; you set a basis you can reasonably explain. For AI chat tools, your chat history works well. At the end of each month, look back through the history and note the rough ratio of work to personal conversations. A few months of notes gives you a documented basis. A figure grounded in records is far more convincing than a gut feeling of "probably 80% work." The math itself is simple. For example, if a $20 monthly subscription is estimated at 70% business use, you deduct $14 a month. Record the remaining 30% as a personal withdrawal (owner's draw) and the books stay cleanly separated.
Some tax systems treat mixed-use expenses more strictly than others, and in some countries the rules depend on which type of return or filing method you use. Check how your jurisdiction handles partially personal expenses before relying on a split.
You can also avoid splitting altogether by separating accounts. Keep the paid account strictly for work and move personal chatting to a separate free-plan account. Then the paid subscription can be treated entirely as a business expense, and there's no history to review each month.
How to record API usage billed in a foreign currency
API usage differs from a subscription: the amount changes every month, and it's often billed in US dollars. If you report in another currency, use the converted amount at the time the payment is settled. With a credit card, the simplest approach is to record the amount in your home currency as it appears on the card statement, which also documents the exchange rate.
For supporting documents, download the invoice or usage statement PDF from each service's dashboard. A card statement alone shows only a single line with a service name, which makes it hard to explain what the expense was. Keeping a record of monthly usage alongside the statement makes later reviews much easier.
Choosing models carefully also helps keep these costs stable. Within the same provider's API, a flagship model and a lightweight model can differ in price per token by an order of magnitude. Using the lightweight model for drafts and formatting and saving the flagship model for final polish before delivery goes a long way toward smoothing out the monthly bill.
Note: price differences between models broadly track model size. For a quick explanation of the size metric that shows up on pricing pages, the glossary entry on parameters published by osFoundry is concise and worth skimming before you dig into a pricing table.
Finally, indirect taxes. Buying digital services from overseas providers can be treated differently for VAT, GST or sales tax than domestic purchases, and some countries use a reverse-charge mechanism. If you're below the registration threshold this often has little practical impact, but if you're registered for VAT or a similar tax, this is the one area worth confirming with an accountant.
FAQ
If I only use free plans, is there anything to deduct?
No spending means no expense. Payments become deductible from the month you switch to a paid plan. That said, books or course fees bought to learn AI tools can still be deductible even while you're on a free plan, as long as you actually paid for them.
What about AI subscriptions paid before I started my business?
In many countries, spending that can be shown to be preparation for launching the business can be treated as start-up costs. Keep statements from before your official start date so you can claim them later if your rules allow.
How precise does the business-use percentage need to be?
Being able to show a basis matters more than accuracy to the single percentage point. Setting the ratio from records such as chat history or working days, and applying the same basis every year, is generally considered sufficient. If you change the basis, write down why.
Top comments (0)