For Developers

Build filing into your software.

Automate CT600 and Companies House returns with our intuitive REST API. Focus on building your product, and let us handle the complexities of tax submissions.

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FEATURES

Everything you need to automate filings

REST API

Predictable REST endpoints with standardized JSON responses and intuitive resource URLs.

API Key Auth

Secure authentication using an X-API-Key header. Generate live and test keys instantly.

CT600 & CH Filing

Submit seamlessly to both HMRC and Companies House programmatically in a unified request.

Auto Tax Calculation

Corporation tax and relevant schedules are computed automatically from provided P&L data.

Document Generation

Retrieve generated PDF accounts, CT600 forms, and compliant iXBRL documents via API.

Status Polling

Track submission status reliably in real-time through comprehensive polling endpoints.

WORKFLOW

Simple and predictable

Add Company (via CH number)

Get Filing Periods

Create & Save Filing

Submit to HMRC/CH

Poll & Download

QUICK START

Minutes to integrate

Our API is designed to be self-explanatory. Create a filing with a single request.

bash

curl -X POST https://api.wefile.co.uk/v1/filings \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "company_number": "12345678",
    "period_start": "2023-01-01",
    "period_end": "2023-12-31"
  }'

PRICING

Standalone developer package

For Developers

API Package

.../year

Up to 300 programmatic filings per year
REST API with API key authentication
CT600 & Companies House submissions
Full document generation & download
Webhook-ready status polling
12 months access

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FAQ

Frequently asked questions

The API package includes up to 300 successful filings per year via our REST API. You get access to live and test API keys, full document generation (CT600, accounts, iXBRL), and webhook-ready polling.

No, the API package is a standalone subscription designed specifically for software developers and platforms. It operates independently of our standard Accountant Membership plans.

Upon subscribing, you can generate API keys from your developer dashboard. We provide both sandbox keys for testing integration without submitting real data, and live keys for production filings. Pass your key in the X-API-Key header of your requests.

The API package allows for up to 300 successful filings per year. Rate limits for API requests are generous enough to support standard polling and submission workflows, but we recommend checking our API documentation for the exact endpoints limits to avoid throttling.

Our API supports joint filings to both HMRC (CT600) and Companies House. You provide the raw financial data, and our engine automatically calculates the tax, generates the required iXBRL documents, and handles the submission protocols for both agencies.

API subscribers receive priority technical support. You can reach out to our dedicated developer support team via email or through the support ticketing system in your dashboard. Our engineers are on hand to help with payload structuring, sandbox testing, and submission debugging.