Thirty Days to 19 September: Ireland Bi-Monthly VAT July–August
As of 20 August 2026, Irish bi-monthly VAT traders have thirty days to file the July–August 2026 VAT 3 by 19 September — plus monthly, four-monthly, and annual VAT packs that share the same date.
Revenue’s Calendar of key dates for tax professionals lists 19 September 2026 for bi-monthly VAT 3 return and payment for July–August 2026, together with the Return of Trading Details where the VAT accounting period ends between 1 July and 31 August. As of 20 August — the day after July monthly VAT 3 — bi-monthly traders have thirty calendar days to close the twin-month pack.
The same 19 September date also carries monthly VAT 3 for August, four-monthly VAT 3 for May–August, and annual VAT 3 cycles ending in August. Do not assume “bi-monthly only” when your ROS profile still shows a monthly or annual obligation.
Who must act by 19 September
Bi-monthly VAT-registered traders whose period is July–August 2026 must file and pay by 19 September 2026, with RTD where the VAT accounting period ends in that window.
Traders on the 9% restaurant and catering rate from 1 July 2026 should keep July and August meal vs accommodation splits clean before the bi-monthly consolidation — guest accommodation at 13.5% must not be rolled into 9% catering lines.
IOSS monthly returns remain a separate diary (July IOSS due 31 August; August IOSS due 30 September) and do not replace domestic VAT 3.
Thirty-day prep checklist
Reconcile July and August sales, credit notes, and import VAT now — do not leave twin-month matching for the week of 19 September.
Confirm ROS certificates and payment method while key staff are available after the 23 August cash cluster.
Diary PAYE for August (14 September return; 23 September ROS payment extension) so payroll cash does not collide with VAT authorisations.
Use a dual-market VAT calculator for estimates while packs are in draft — final ROS figures still need your adviser’s review.
How FinnAccountings helps with bi-monthly VAT packs
Organised July–August ledgers make VAT 3 review faster. FinnAccountings helps Ireland and UK businesses prepare bookkeeping and VAT packs with Chartered Accountant insight before you or your Chartered Accountant (Ireland) or ICAEW/ACCA adviser files. Start a free trial for review-ready drafts — we prepare records; we do not file ROS VAT 3 returns on your behalf.
Related reading
Today’s twenty-nine-day bi-monthly countdown continues this briefing.
The earlier bi-monthly July–August briefing still maps the full September cluster.
Clear Sunday ROS cash on 23 August before you deepen September VAT workpapers.
For dual-market VAT estimates while you prep packs, use the free calculator.
Sources & references
This article draws on official guidance from the sources below.
- Calendar of key dates for tax professionals
Revenue (Irish Tax and Customs) · Accessed 2026-08-20 - When VAT becomes payable
Revenue (Irish Tax and Customs) · Accessed 2026-08-20 - How do you complete a VAT 3 return?
Revenue (Irish Tax and Customs) · Accessed 2026-08-20
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