Frequently asked questions

iXBRL (Inline eXtensible Business Reporting Language) is a global reporting standard that embeds machine-readable XBRL tags^tag directly inside an HTML document. The result looks like a normal set of accounts when viewed in a browser, but each figure is also tagged so software at HMRC and Companies House can read, validate and extract it automatically.

HMRC has required iXBRL for Corporation Tax return attachments since 2011. Companies House currently accepts several filing routes; software-only iXBRL filing was due to become mandatory from 1 April 2027, but that reform was paused by Companies House in January 2026, with no new date yet set. See our full update for the detail.

Minimum tagging covers a defined core set of elements — company name, registration number, key balance sheet totals — and is generally sufficient for Companies House filing of micro-entity and small company accounts. Full tagging maps every note, disclosure and comparative figure to the taxonomy, and is required for HMRC Corporation Tax computations and for larger or more complex accounts.

We tag against the current FRC taxonomies for FRS 101, FRS 102 and FRS 105, the UK GAAP taxonomy, and the IFRS taxonomy for groups reporting under international standards — always the version currently accepted by HMRC and Companies House.

Minimum tagging for straightforward micro-entity accounts is typically same-day. Full tagging for HMRC computations or more complex accounts usually takes 24–48 hours. Priority same-day options are available for both.

We accept PDF, Word and Excel accounts, along with exports from common accounting software such as Xero, QuickBooks and Sage.

Yes. iXBRL keeps the human-readable layout of your accounts intact — the XBRL tags are embedded invisibly within the HTML, so anyone viewing the document in a browser sees the same accounts you sent us.

Yes. We run a dedicated bulk-tagging workflow for accountancy practices, with volume-tiered pricing, a named account handler, and batch upload and status tracking. See our pricing page or get in touch.

Yes. Our pre-submission review service independently validates already-tagged accounts against the current HMRC and Companies House schemas and checks taxonomy element selection, flagging anything likely to cause a rejection.

Every document we deliver is validated against the current schema before it reaches you, which is designed to prevent rejections. In the rare case a tagging-related rejection does occur, we correct and re-validate the document at no extra charge.