Build filing into your own software
The Filing API is for other companies' software: send a return or a set of accounts, and follow each filing until HMRC or Companies House has decided. It is planned, but it is not available. Request a meeting to talk about it.
What you can file
CT600 returns
Corporation Tax returns, sent to HMRC with their iXBRL accounts and computations.
Accounts
iXBRL accounts, sent to Companies House.
Dormant and trading companies
You send the figures, and the API validates and sends them. It does not work out the tax.
Status tracking
Every filing is followed from sent to decided, with HMRC's and Companies House's own words when they reject.
How it works
- A REST API that takes and returns JSON, with API key authentication.
- A sandbox to build and test against before any live filing.
- Status polling that returns the detailed HMRC and Companies House rejection payloads, not a summary of them.
- A filing is saved before it is sent, and a lost reply is never sent a second time by itself.
How to start
Request a meeting
Tell us what you build, which filings you need and roughly how many a month.
We agree how it works
Who files for whom, what each of us is responsible for, the volumes and the price.
Sign the agreement
Access is by agreement. There is no sign-up form and no self-serve key.
Sandbox key, then live key
You build against the sandbox. A live key follows when you are ready.
What it costs
Partners are priced per request. The price is agreed with you in the meeting, so that it fits what you send and how often. There is no price list.
If you file for your own companies on a paid TaxPip plan, the API is included: there is no separate API tier and no fee for each filing. The pricing page has the plans.
What you will see once it is sent
Sending a filing from TaxPip is planned, but it is not available. When it is, every filing is saved before it is sent and followed until the authority has decided. These are the only states it can be in, and they only move forward.
Sending
Saved first, then sent. A crash cannot leave a filing that nobody has a record of.
Received
The authority has the message and has not decided.
Accepted
The authority has accepted it. The answer is kept with the filing.
Or it stops somewhere else
Rejected
The authority has said why not, and its reason is shown as it was sent.
Refused
The authority refused the message itself, so nothing was filed.
Unknown
The reply was lost, so there is no telling whether it arrived. It is never sent a second time by itself: you ask the authority, or say it never arrived.
What it is not
Not the tax engine.
You send the figures. The API validates, sends and tracks them. TaxPip's own tax calculations are built for companies that let property.
Not self-serve.
Access is by agreement, after a meeting.
Not a way round the filer.
Each filing is made with the company's own credentials, which are used to send it and are not stored.
Not advice.
No accountant has reviewed it, and whoever files is responsible for what is filed.
Questions
Do you store my customers' credentials?
No. The Government Gateway details and the Companies House presenter details arrive with each request, are used to send it, and are dropped. They are never logged or returned.
The one exception is the Companies House presenter details, which the filer can ask to be kept sealed for up to 14 days, so that the result can be checked without them.
What do I get back when a filing is rejected?
The authority's own rejection, in full: the codes and the text that HMRC or Companies House sent. A summary would hide what your customer needs to fix.
Is there a sandbox?
A sandbox is part of the plan, and it is not available. It is one of the things to settle in the meeting.
Can I use it for my own companies?
Yes. Your own companies on a paid plan can use the API without a separate fee. The meeting is for other companies' software.
Keep reading
- Products: accounts, tax returns and filings
Annual accounts, Corporation Tax, VAT, Self Assessment, the confirmation statement and closing a company: what each is and what TaxPip does for it.
- Security and data protection
How sign-in, accounts and records are protected, where the service runs, and what has not been done yet.
- Questions about accounts, tax figures and filing
Is it an accountancy firm, does it file for me, which companies and statements it supports, and what the AI does.
Tell us what you are building
Access starts with a meeting. The button opens an email to us with the questions we will ask. Nothing is stored on this site.