Research
Research data API
The figures on our research pages, as JSON files you can read without a key.
Each file holds the same figures as one of our research pages. They count companies that chose an accountancy activity code (SIC 69201, 69202 or 69203) in the Companies House company data file: our own count is 54,295 trading on 1 October 2026, worked out as set out in how our research works. A company is not a practice, and sole traders and partnerships are not included. The files hold totals and shares only: no single company, and no owner names.
Files
| File | What it holds | Page with the same figures |
|---|---|---|
/api/research.json | Companies by status, then trading companies by ownership type, size band and company age, and companies by year of incorporation. | Who owns UK accountancy firms |
/api/filing-health.json | Overdue accounts and confirmation statements, and registered charges, for accountancy companies and for all UK companies. | Do accountancy firms file on time? |
/api/accounts-calendar.json | How many UK companies have accounts and confirmation statements due in each of the next 12 months. | When are UK company accounts due? |
Any website can read them (CORS is open). The full description is in openapi.json.
For AI assistants (MCP)
The same files are available through a read-only MCP server at https://therightaccountant.co.uk/mcp (streamable HTTP). It has one tool, get_accountancy_research, and one resource for each file. The manifest is at /.well-known/mcp.json.
Reuse
Our tables and figures are free to reuse under the Creative Commons Attribution 4.0 licence (CC BY 4.0). Credit The Right Accountant and link to the page you used. Sources, definitions and limits are on how our research works.