The best billing software for a SaaS startup depends first on who you want to carry sales tax and compliance. A merchant of record sells on your behalf and handles tax on each sale; a billing engine runs your plans and invoices on your own payment setup, leaving tax with you.
The first time a customer in another country signs up for your product, billing stops being a checkout button. Suddenly there are questions about which tax applies, who has to register where, what goes on the invoice and what happens when a card fails at renewal. Most founders meet those questions in the same month they're trying to ship features and close their first annual deal.
So this list isn't sorted by feature count. It's sorted by the decision that shapes everything after it: whether someone else sells on your behalf, or whether you run billing yourself on top of a processor. Nine tools, in no particular order and with no crowned pick, because the right answer for a two-person developer tool isn't the right answer for a sales-led company with enterprise contracts.
Who carries the tax: the question to settle before any demo
Some of these tools describe themselves as a merchant of record. In plain terms, they're the legal seller of your software. The customer buys from them, they handle the tax compliance on that sale, and they pass the proceeds to you. You give up some control over the checkout and the customer relationship in exchange for a much shorter compliance to-do list.
The others are billing engines. They run subscriptions, usage tracking and invoices on top of a payment processor you set up yourself. You keep full control of your checkout, your data and your contracts, but tax and compliance stay on your desk, which usually means adding a tax tool or an adviser as you grow.
Neither model is better in the abstract. A merchant of record suits founders who'd rather not think about tax registrations at all. A billing engine suits companies that want control, already have finance help, or sell in ways a merchant of record may not support well, such as custom enterprise contracts. Settle this one first and you'll halve your shortlist. Tax rules vary by country and change often, so check your obligations with your tax authority or an accountant rather than relying on any vendor's summary.
The two camps, plus the usage specialists
Merchant of record: someone else sells for you
Paddle covers payments, subscriptions and tax for SaaS and mobile apps in one platform. Lemon Squeezy is aimed at software companies and digital products, with tax compliance as the headline. FastSpring leans on selling globally under its merchant-of-record model. Polar is the developer-focused option, and it's the one in this camp that also talks about usage-based billing.
Subscription engines: you run billing on your own processor
Stripe Billing is the natural first look if you already take payments through that processor, with plans set up by API or in the dashboard. Chargebee is built for SaaS and AI companies and goes further into revenue operations. Recurly puts weight on failed-payment recovery and churn reporting, which matters once renewals make up most of your revenue. For a wider comparison of this camp, see our guide to recurring billing tools for subscription businesses, and our closer look at the billing product inside Stripe goes deeper on that one.
Usage specialists: when customers pay for what they consume
If you charge per API call, per seat hour or per AI request, a general subscription tool can start to creak. Lago runs usage, subscriptions and hybrid plans, and it's the only tool here offering self-hosting. Orb is built around usage-based billing and changing how you charge as usage and margins shift. Our roundup of usage-based billing platforms compares more options in this camp.
All nine, in no particular order
Chargebee
Best for: SaaS and AI companies that want billing and revenue operations covering recurring subscriptions through to usage-based charging, run on a processor they set up themselves.
FastSpring
Best for: Software sellers who want a merchant-of-record model that, in the vendor's words, lets them sell globally and stay compliant, with a wide range of local payment methods.
Lago
Best for: Engineering-led startups that want usage, subscriptions, hybrid plans and invoicing as a hosted service, with self-hosting available if they'd rather run it themselves.
Lemon Squeezy
Best for: Founders selling SaaS or digital products who want a merchant of record to take the tax compliance burden off them, so they can focus on growth.
Orb
Best for: Software companies charging by usage that want to design and change how they charge as their product, usage and margins shift over time.
Paddle
Best for: SaaS and mobile app companies that want one platform handling billing, tax and compliance, rather than stitching a processor, tax tool and billing system together.
Polar
Best for: Developers building software who want a merchant of record covering payments, subscriptions and usage-based billing, with global tax handled for them.
Want AI doing the heavy lifting in your marketing?
I build the systems that handle the boring 80 percent, so you get your week back. Done properly, with the human kept in.
Recurly
Best for: Subscription businesses that want plans, billing, failed-payment recovery and churn reporting in one platform, sitting on top of their own payment setup.
Stripe Billing
Best for: Startups already taking card payments through that processor who want recurring and usage-based plans set up by API or dashboard, plus AI tools the vendor says reduce churn.
Side by side: model and best fit
| Tool | Model | Best fit |
|---|---|---|
| Chargebee | Subscription engine | SaaS and AI companies with mixed plans |
| FastSpring | Merchant of record | Founders selling to customers in many countries |
| Lago | Usage and subscription engine | Teams that may want to self-host |
| Lemon Squeezy | Merchant of record | Small teams selling software and digital products |
| Orb | Usage engine | Products charged by consumption |
| Paddle | Merchant of record | SaaS and mobile apps wanting tax handled |
| Polar | Merchant of record | Developers who need usage billing too |
| Recurly | Subscription engine | Subscription businesses chasing failed payments |
| Stripe Billing | Subscription and usage engine | Startups already on that processor |
If your business isn't software at all and you're comparing invoicing tools for services, our general guide to billing software for small businesses is the better starting point.
Questions to ask before you wire billing into your product
Billing is one of the hardest systems to swap once customers are on it, so these questions are worth an hour now.
- Who is the seller on the customer's receipt? With a merchant of record it's the vendor. With a billing engine it's you. That affects tax, refunds and how your brand appears.
- How will you charge in a year? If usage or AI credits are likely, check usage billing works now rather than planning a migration later.
- Can you move your subscribers out? Ask how customer and card data would be exported if you switch, and who has to be involved.
- Who handles failed renewals? Look for retry and recovery tools, because lost renewals quietly drain a subscription business.
- Does it fit how you sell? Self-serve checkout and signed enterprise contracts need different things. Make sure your largest likely deal type is supported.
- What do you still own on tax? Even with a merchant of record, confirm in writing what's covered, and check the rest with an accountant.
My advice on where founders should start
If you're a small team selling self-serve software to customers in lots of countries, and nobody on the team wants to become a tax expert, start with the merchant-of-record camp. You'll trade some control for months of admin you won't have to do, and that's usually the right trade at the start.
If you're sales-led, already have finance help, or want your checkout and customer data entirely in your hands, go with a subscription engine on your own processor, and plan time for tax tooling. If your product is charged by consumption, put the usage specialists on the shortlist from day one, because retrofitting usage billing onto a plain subscription setup is a job nobody enjoys. Whichever way you go, keep a clean export of your plans and subscribers, so the decision you make today never traps you later.
Do you make billing or subscription software for SaaS companies? Tool makers can ask to be considered for a featured place on this list.
Want your tool on this list? Featured spots and reviews here are paid partnerships. Here's how to partner with me.
Frequently asked questions
What is a merchant of record for SaaS?
A merchant of record is the company legally selling your software to the customer. It handles tax compliance on each sale and pays the proceeds on to you, so you don't have to manage tax registrations yourself. You give up some control over checkout in return.
Should an early-stage SaaS startup use a merchant of record or a billing engine?
Many early-stage teams selling self-serve to customers in several countries start with a merchant of record to avoid tax admin. Teams that sell custom contracts or want full control often choose a billing engine on their own processor. Check your tax position with an accountant either way.
Do I still need a tax tool with a billing engine?
Usually, yes. A billing engine runs your plans and invoices, but the tax and compliance work stays with you. Rules vary by country, so check with your tax authority or an accountant about what applies to your sales.
What's the difference between subscription billing and usage-based billing?
Subscription billing charges a set plan on a schedule. Usage-based billing charges for what a customer consumes, such as API calls or AI requests. Many SaaS products now mix the two, so check a tool handles both before you commit.
Can I switch billing software later?
You can, but it's harder than most tool switches because live subscriptions and card details have to move. Ask any vendor how exports work before you sign up, and keep your plan definitions documented outside the tool.
Is self-hosted billing a good idea for a startup?
It can suit engineering-led teams that want control over their data and infrastructure. The trade-off is that you run and maintain it. Most startups start hosted and only consider self-hosting when they have a clear reason.
