You build the tax form screens in your own app, with your own design. Taxbit tells your app which questions to ask, checks the answers, and stores the finished form.

No tax knowledge needed. You don't hard-code any questions, labels or validation rules.
Your look. Use Taxbit's ready-made fields, or swap in your own components.
Web and mobile. React and iOS clients both work today.

Beta — building with design partners. Taxbit is shaping the interface alongside the teams integrating now, so names and options can still change. The React and iOS clients collect and submit W-9s against a Taxbit development environment, on the same tax engine as the Taxbit React SDK. Talk to your Taxbit contact about early access.

You build the front end. The Logic API gives your team more control, and more work. If a styled, ready-made form fits your needs, the Taxbit React SDK is faster to launch. Compare the two.

W-9 and self-certification work end to end today. W-8 (BEN, BEN-E, IMY) and DPS are next. See Development status.

Next: see a W-9 integration, or read the integration guide.

Who does what

You	Taxbit
Choose where the form appears in your app	Decides which questions to ask, based on the answers so far
Choose how it looks	Writes every label and error message, translated into 40+ languages
Decide what happens when it's done	Checks TINs, addresses and the other answers
	Confirms the form is complete, then stores it

How it works

sequenceDiagram
    participant App as Your app
    participant C as Client library
    participant TB as Taxbit
    App->>C: Render the form
    C->>TB: The answers so far
    TB-->>C: The questions to show now, their labels, any problems
    C-->>App: Draw the returned fields, in your design
    Note over C,TB: repeats whenever an answer changes the form
    C->>TB: Submit, once the form is complete
    TB-->>App: document_id receipt

Your app shows the form Taxbit sent, in your design.
When an answer changes the form, for example picking "LLC", the client library sends the answers to Taxbit.
Taxbit sends back the updated form: the questions to show now, their labels, and any problems.
When Taxbit says the form is complete, the client library submits it and you get a receipt.

You don't write any of this loop. The client library runs it for you.

Is it right for you?

Most teams should start with the Taxbit React SDK. It's fully built. You add it to your app and style it to match your brand. Choose the Logic API only when you need to own the screens themselves.

In both, Taxbit guides the questions. Each person only sees the questions that apply to them, based on what they've already answered or what you already know about them. The difference is who builds the screens those questions appear on.

	Taxbit React SDK (recommended for most)	Logic API (Beta)
Availability	Generally available	Beta, with design partners
Who decides the questions	Taxbit	Taxbit
Who builds the screens	Taxbit. You style them.	You. You build and maintain them.
Best for	Getting live quickly, with a branded, proven form	Teams that need tax collection inside their own design system or flow, or a native mobile app
Platforms	React	React and iOS
Effort	Low: install, configure and style	Medium to high: you build the front end, and Taxbit supplies the questions and rules

Already collecting tax information yourself? The Taxbit React SDK and the Logic API both guide your users through the questions. If you gather the information in your own forms or systems and only need to check it, use the Validation API instead. You send the completed information, and Taxbit tells you whether it's valid and what needs fixing. There's an endpoint per document type — W-9, W-8BEN, W-8BEN-E and self-certification.

Next steps

Walkthrough — how a W-9 works under the hood
Integration guide — authentication, tailoring, and your own components