Ireland iXBRL: Revenue Accepts 2026 Irish Extension Taxonomies

On 21 July 2026, Revenue published eBrief No. 115/26 confirming that ROS now accepts iXBRL financial statements tagged with the 2026 Irish Extension taxonomies. Tax and Duty Manual Part 41A-03-01 (Electronic filing of financial statements with Corporation Tax returns) has been updated so paragraph 1.6 lists the new schemas alongside earlier accepted versions.

For Irish limited companies and their agents, this matters whenever you attach iXBRL accounts to a Form CT1. Filers should move to the taxonomy that matches the accounting framework and period of the financial statements — Revenue expects new taxonomies to be used at the earliest opportunity once accepted.

The updated accepted list includes FRS 101 Extension 2026 (Irish Final), FRS 102 Extension 2026 (Irish Final), and EU IFRS Irish Extension 2026 (Final). Schema references point to the Financial Reporting Council Ireland packages dated 2026-01-01. According to the manual’s applicability notes, these 2026 extensions apply to financial statements commencing on or after 1 January 2025.

Earlier 2025, 2023, 2022, and 2019 Irish Extension taxonomies remain listed for the periods they cover. Revenue also keeps a separate list of withdrawn taxonomies (legacy IE GAAP / IE IFRS and older DPL combined schemas) that must not be used. Private taxonomy extensions are still not accepted.

Confirm your tagging or accounts-production software has loaded the 2026 Irish Extension packages and can validate against the FRC Ireland schema URLs before you upload to ROS. Where a company prepares FRS 102 accounts for a period starting in 2025 or later, prefer the 2026 FRS 102 Irish Extension rather than an older package that predates the current framework wording.

Re-check full tagging discipline in Part 41A-03-01: monetary line items and notes should use appropriate tags; leaving totals untagged while tagging components (or the reverse) remains a common rejection risk. Align CT1 mandatory items with the iXBRL mandatory items table in the manual so corporation tax and accounts submissions stay consistent.

If you file for multiple group entities, schedule a short taxonomy upgrade window with your agent or software vendor — do not wait until the CT1 deadline night to discover a validation failure against an outdated schema.

iXBRL remains the format Revenue requires for electronic financial statements accompanying corporation tax returns for in-scope companies. The eBrief does not change filing deadlines or who must file — it updates the dictionary of tags ROS will accept. Pair taxonomy readiness with clean trial balances and exportable working papers so CT1 prep is not blocked by tagging rework.

FinnAccountings helps Irish and UK finance teams organise bookkeeping and tax prep drafts with Chartered Accountant insight before you or your Chartered Accountant (Ireland) adviser signs off filings — start a free trial to keep corporation-tax packs review-ready while your agent handles ROS iXBRL upload. Use the free tax calculator for high-level Ireland and UK liability estimates only.

Companies watching large-case compliance should also read our Co-operative Compliance Framework €350m briefing. For VAT maths ahead of ROS VAT3 prep, open the free Ireland VAT calculator and VAT Services Ireland.