How to file in iXBRL
There's no free government tool for this in the UK — here's how it's generally done, and the trade-offs between the main routes.
Step 1: get your accounts into taggable shape
Whatever format your draft accounts exist in — Word, Excel, a PDF from your bookkeeper, an export from accounting software — this is the starting point for tagging, whichever route you take next.
Step 2: choose your tagging route
Self-tag in-house
Practice or filing software with built-in iXBRL generation. Works well if someone on your team tags regularly enough to stay confident in it.
Fast, but worth checking
Some services lead with automated best-guess tagging for speed. Faster isn't always more accurate — worth checking whether a qualified person reviews the output before you rely on it.
Send it, get it back tagged
Our approach: element-by-element mapping, not automated best-guess tagging, independently reviewed by a second qualified accountant before delivery. See our process.
Step 3: validate before you file
Whichever route you take, validate the tagged document against the current taxonomy before submission — this is what catches most rejections before they happen. See our quality checks.
Step 4: file with the right regulator
Since the joint HMRC/Companies House filing service closed on 31 March 2026, CT600 and Companies House accounts are submitted separately, each through commercial software or an agent. See our update on joint filing closing.
Frequently asked questions
Can I file iXBRL accounts myself without any software?
No — both HMRC and Companies House require iXBRL-tagged documents produced through commercial software, an accountant, or a specialist service. There's no free government tool for either filing.
Is automated tagging reliable on its own?
Automated tools can speed up the mapping, but accuracy varies. We'd suggest checking whether a qualified person reviews the tagged output before it's filed, rather than relying on automation alone.
Can I still submit to HMRC and Companies House together?
No — the joint filing service that allowed this closed on 31 March 2026. The two filings are now submitted separately, whichever tagging route you use.
Skip the tooling decision entirely
Send us your accounts — we tag, validate, and hand back a filing-ready document, typically within 24 hours.
Get a free quote