AI companies are going global faster than any group of businesses we’ve seen. Our data shows that by their third year, the 100 largest AI companies on Stripe sold into an average of 120 markets, compared with about 50 for the fastest-growing SaaS companies.

This growth also comes with tax complexity. Sales tax, value-added tax (VAT), and goods and services tax (GST) generally depend on where the customer is located, regardless of the business’s size or whether it has formally launched in the market. As a result, a small, self-serve AI company can face tax registration and collection requirements across dozens of countries before it has dedicated tax operations.

AI companies are also changing how software is sold. Instead of charging one fixed subscription each month, many combine subscriptions with usage fees, prepaid credits, and charges for API calls, data lookups, or generated images that can be a fraction of a cent. These pricing models make it harder to determine when tax is due and how much to collect.

This guide covers three of the biggest tax surprises for AI companies and what you can do to get ahead of them.

Microtransactions can leave you on the hook for sales tax you never collected

A traditional SaaS invoice applies tax to a monthly subscription total. AI products can instead generate thousands of much smaller charges, sometimes only a few cents each. As software agents begin buying services from other agents through specifications such as the Machine Payments Protocol, some of those transactions might even fall below 1¢.

While payment providers can record these amounts precisely, tax reporting systems generally do not. The EU VAT Directive leaves detailed rounding rules to each country, but invoices, accounting systems, and tax authority portals in many euro-area countries record VAT to two decimal places. This means that rounding can materially change the tax you collect and record.

Consider a 2¢ API call taxed at 20%. The tax on that call is 0.4¢, which rounds down to zero. If tax is calculated and rounded separately for each call, the customer might not pay any tax, even though the transaction is taxable. Across millions of calls, that uncollected tax can add up, and you would still be responsible for paying it to the tax authority. If the same calls were totaled on a monthly invoice before tax was calculated, the tax would be recorded and collected from the customer.

Every country has rules that determine when tax is due. If you don’t collect tax as required, the tax authority might issue an assessment specifying the amount you need to pay—often with interest and penalties. And because the tax was never collected from customers, it might end up coming from your margin.

What you can do about it: Make sure your billing setup adds up small usage charges before tax is calculated. Metronome, Stripe’s usage-based billing solution, can aggregate usage over a set interval and create invoice items from the total. Stripe Tax then calculates tax on those invoiced charges, rather than on each API call or other usage event. This can help reduce the risk that tax rounds down to zero before it is collected.

You might owe VAT before a customer uses a single AI credit

Tax is relatively straightforward for SaaS companies because they charge the same subscription fee each month, add the applicable tax, and issue an invoice. On the other hand, two out of three companies on the Forbes AI 50 use some form of usage-based pricing, often alongside a subscription. A single customer might pay a fixed monthly fee, buy credits in advance, and incur additional charges for tokens, API calls, generated images, or completed workflows. The information needed for a correct invoice—such as what was sold, when it was used, and how it should be taxed—has to be pieced together from usage, credit, and subscription data.

Suppose a customer buys $10,000 in usage credits for your AI product. Do you charge VAT when the customer buys the credits, or only when they use them? In the European Union, the answer depends on what is known at the time of sale. If the credits can only be used for one service and taxed at one rate in one country, VAT is generally due up front. If the credits can be spent on different services, which are each taxed differently, or used by customers in different countries, the credits might qualify as multipurpose vouchers, and VAT is due only when the credits are used. Contracting details, such as whether unused credits expire or are tied to a subscription, can also impact the timing of when VAT is due. If your billing system tracks usage, but your tax system only sees the original purchase, VAT can end up in the wrong period.

What you can do about it: Build tax into your pricing model from the start. Before launch, decide when each charge becomes taxable and make sure your usage, billing, and tax records match. Stripe Billing lets you capture and bill for usage, and Tax can calculate tax on that usage. For more complex usage-based models, Metronome handles metering, pricing, and billing, then sends invoices to Stripe for payment and tax. In either setup, you can trace each invoice to what the customer used and when.

One sale can trigger tax obligations in a new country

Indirect taxes apply almost everywhere based on where the customer is located. That rule means that self-serve digital companies can incur tax obligations wherever customers sign up, even if their business doesn’t have a local presence in that market.

AI companies are triggering these tax obligations faster. You don’t need meaningful traction in a market to create a tax obligation, either. A growing number of countries require foreign sellers to collect tax with little or no minimum sales threshold. A non-European business, for example, can incur an EU VAT obligation as soon as it sells a single subscription to an individual in the European Union.

In the United States, sales tax rules vary by state and, in some cases, by city. The same product can also receive different tax treatment depending on where the customer is located. For example, a subscription-based hosted AI assistant is generally taxed as prewritten software in New York and as data processing in Texas, where tax applies to 80% of the charge.

What you can do about it: Record where each customer is located and what they buy, then monitor when sales in each market require you to register and collect tax. This gives you time to decide how you want to handle the obligation before a filing deadline arrives.

You can make that decision by market or product. If you want to remain the merchant of record, Tax can monitor thresholds and calculate and collect tax while you retain control over the customer relationship. In markets where you want to transfer tax responsibility, Stripe Managed Payments can act as the merchant of record and handle registration, collection, filing, and remittance.

Learn more about how Tax works with Billing and Metronome to apply sales tax, VAT, and GST to charges at the right time, or contact us.