How to Automate Invoice Processing for HVAC Companies Using Make.com

If you run an HVAC company, you already know how this goes. Job wraps up Friday afternoon. Technician drives home. Invoice doesn't go out until Tuesday. Client forgets. You follow up. They pay late. You chase it again.

The whole thing is automatable. Here's how to build it with Make.com.

What You're Building

A workflow that watches for completed jobs, pulls the job details, generates an invoice from a template, and emails it to the client as a PDF. All without anyone touching it.

Specifically:

1. Watches for completed jobs in your CRM or a Google Sheet
2. Pulls job details (client name, address, technician, services performed, total)
3. Creates a professional invoice from a Google Docs template
4. Emails it to the client automatically
5. Logs the invoice so nothing gets sent twice

No code required. Free to start on Make.com's basic plan.

What You Need Before Starting

• A Make.com account (free tier works fine for low volume)
• Google account with Drive, Docs, and Gmail
• Your job data somewhere Make can read it: Google Sheet, Airtable, Jobber, ServiceTitan, or HouseCall Pro all have direct Make integrations
• An invoice template, which we'll set up in Step 1

Step 1: Build Your Invoice Template in Google Docs

Open a Google Doc and lay out your invoice the way you want it to look. For any field that changes per job, use double curly braces as placeholders:

Client: {{client_name}}
Service Address: {{service_address}}
Date of Service: {{service_date}}
Technician: {{technician_name}}

Services Performed:
{{services_performed}}

Parts: {{parts_list}}
Labor: {{labor_cost}}
Parts Total: {{parts_total}}
Tax: {{tax}}
Total Due: {{total_due}}

Payment Due: {{due_date}}

Save the doc inside a Google Drive folder called something like "Invoice Templates." Make will use this to generate a new document for each job.

Step 2: Set Up Your Data Source

If you track jobs in a Google Sheet, add columns for each placeholder above. You'll also want a column called "Invoice Sent" that starts blank.

If you use Jobber, ServiceTitan, or HouseCall Pro, you can trigger the scenario directly when a job is marked complete. No spreadsheet needed.

For this tutorial, we'll use the Google Sheet approach since it works for everyone.

Step 3: Build the Make.com Scenario

Log into Make.com and create a new scenario. You need four modules:

Module 1: Google Sheets — Search Rows

Connect your sheet and filter for rows where "Invoice Sent" is blank. Set the limit to 1. Processing one invoice at a time keeps things clean and easier to debug.

Module 2: Google Docs — Create Document from Template

Select your invoice template. Map each {{placeholder}} to the matching column from your sheet. Point the output to a folder like "Invoices/2025" so everything stays organized.

Module 3: Google Drive + Gmail — Convert to PDF and Send

Add a Google Drive module to export the new doc as a PDF, then a Gmail module to send it. Set the recipient to {{client_email}}, attach the PDF, and write a short professional body. Something like:

Hi {{client_name}}, please find your invoice attached for the service on {{service_date}}. Let us know if you have any questions.

Module 4: Google Sheets — Update Row

Mark "Invoice Sent" as TRUE so this job never gets invoiced again.

Step 4: Test It

Add a row to your sheet with real-looking test data. Run the scenario manually. Confirm:

• The Google Doc was created with the right fields filled in
• The PDF came through on the email
• The row is now marked as sent

Fix anything that looks off before scheduling it.

Step 5: Schedule It

Set the scenario to run every hour, or once a night at 6 PM, whichever fits your workflow. From that point on, any completed job without an invoice gets one sent automatically.

What This Actually Saves You

Businesses that automate invoice processing cut processing costs by 60-70% compared to doing it manually. For a small HVAC company sending 15-30 invoices a month, that typically works out to 3-5 hours of admin time per week.

The bigger impact is timing. Invoices go out same-day instead of days later. That change alone tends to move the needle on how fast clients pay.

What to Build Next

Once this is running, two natural extensions:

Payment reminders. If no payment comes in after 14 days, trigger a follow-up email automatically. Same scenario, just add a scheduled check against your sheet.

QuickBooks sync. Add a QuickBooks module right after the Gmail send. The invoice gets created in your accounting software at the same time it goes to the client. Your books stay current without any manual entry.

Both can be added to the same scenario without rebuilding anything.

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If you want this built for your exact setup, whether that's Jobber, ServiceTitan, HouseCall Pro, or a custom CRM, Aplos AI builds these for HVAC companies at a fixed price. Most invoice automation builds come in under $5,000 and pay for themselves in the first quarter.

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Running a different field service stack? Drop it in the comments. Always curious what people are actually using out in the field.