Polar
Why Polar
Polar is a billing platform that acts as a merchant of record, handling international tax compliance, fraud prevention and payouts for digital products and software. It supports subscriptions, one-time purchases and usage-based billing, tracking consumption such as tokens and API calls. It suits AI startups and infrastructure teams that sell usage-based services and want tax compliance handled from day one.
What it does
Polar is a billing platform for software and digital products that acts as your merchant of record. You sell one-time products, subscriptions, pay-what-you-want or free products, and Polar handles checkout, tax, invoicing and payouts. It also does usage-based billing, with meters for things like API calls or tokens, seat-based pricing and unit-based pricing.
Customers get automated benefits after buying, such as licence keys, file downloads, GitHub repository access or Discord roles.
Why you would need it
Selling software to customers in many countries means VAT, GST and sales tax rules in each of them. A payment processor takes the money but leaves the compliance with you. Most small teams either ignore it, which is risky, or avoid selling abroad.
As merchant of record, Polar becomes the seller. It calculates, collects and remits the tax, and you receive a payout. You also skip building a customer portal, subscription renewals and failed payment handling.
Where it fits
Polar is the billing and payments layer of your product. Your app sends usage events in, and Polar turns them into invoices. Your app listens to webhooks to grant access. It replaces a payment processor plus your own tax handling, subscription logic and licence delivery.
It has a migration guide from Stripe. If you only want a processor and handle tax yourself, compare Stripe and Stripe Billing.
What stands out
- Merchant of record. Polar handles international tax compliance, including EU VAT.
- Usage metering. Meters, prepaid credits and cost insights suit pricing by tokens, calls or compute.
- Developer tooling. There are SDKs for JavaScript and TypeScript and for Python, framework adapters for Next.js, Nuxt, TanStack Start, Laravel and BetterAuth, and a sandbox environment.
- An official MCP server. It uses OAuth, so you never paste an API key into your agent.
My take
Polar is built for developers, and it shows in the docs. The setup is a checkout link, a webhook and a few lines of code, and you can start with no monthly fee. The trade-off is simple. You pay a percentage and a fixed amount on each sale, and in return you do not run tax compliance.
I would use it when you sell software globally and do not want a finance project before your first customer. As volume grows, compare the fee on the free plan with the lower rates on the paid tiers, since the answer depends on your sales.
Verdict
Pick Polar when you sell software, subscriptions or usage-based services internationally and want tax compliance handled for you. Skip it if you want to be the seller of record yourself, or if your billing is simple and local, where a processor is enough.
Notes
Your note
Before you choose
Fees follow your sales
Polar takes a percentage plus a fixed fee on each transaction. Paid tiers add a fixed fee each period and lower the rate. Work out your expected volume and compare the tiers, because the cheapest option changes as you grow.
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A merchant of record sets rules
Because Polar is the seller, it has an acceptable use policy, account reviews and a list of supported countries. Check that your product and your country are covered before you build on it.
Usage billing needs clean events
Metering only works if your product emits reliable usage events. Plan the event design before you promise usage-based pricing to customers.
Less control than your own setup
With a processor you own the customer relationship and the tax setup. With a merchant of record you trade some of that for convenience. Think about whether you will need to move later, and how.
Alternatives to compare
Look at Paddle and Lemon Squeezy for other merchant of record options, and Chargebee or Stripe Billing if you keep tax in house.