VAT 8 min read

Twenty-Nine Days to 19 September: Ireland Bi-Monthly VAT July–August

As of 21 August 2026, Irish bi-monthly VAT traders have twenty-nine 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 Friday 21 August — two days before the Sunday ROS cash cluster — bi-monthly traders have twenty-nine 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 diary 19 September

Bi-monthly VAT-registered traders covering July–August 2026, including Return of Trading Details where the VAT accounting period ends between 1 July and 31 August.

Monthly August VAT 3 filers, four-monthly May–August filers, and annual VAT 3 traders whose period ends in August — all share the 19th.

IOSS monthly returns remain a separate track (July IOSS due 31 August; August IOSS due 30 September) and do not replace domestic VAT 3.

Twenty-nine-day prep checklist

Reconcile July and August purchase and sales ledgers after this weekend’s PAYE/RCT/CT cash work so VAT 3 boxes are not waiting on open bank matches.

Confirm RTD requirements early — missing trading details can block a clean VAT 3 submission even when net VAT looks correct.

Diary September PAYE (14 September return; 23 September ROS payment) beside VAT so mid-month ROS sessions stay sequenced.

Keep December year-end CT1 (23 September) on a parallel track if you are both a VAT trader and a calendar-year company.

How FinnAccountings helps with bi-monthly VAT packs

Organised sales and purchase channels make twin-month VAT packs easier to review. 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 VAT 3 or ROS returns on your behalf.

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Related reading

Yesterday’s thirty-day bi-monthly briefing still maps the full September VAT cluster.

Bi-monthly VAT: 30 days to 19 September →

July IOSS still closes at month-end — keep IOSS and domestic VAT diaries separate.

Ireland IOSS: ten days to 31 August →

For dual-market VAT estimates while you prep packs, use the free calculator.

Open free VAT calculator (Ireland & UK) →

Sources & references

This article draws on official guidance from the sources below.

  1. Calendar of key dates for tax professionals
    Revenue (Irish Tax and Customs) · Accessed 2026-08-21
  2. When VAT becomes payable
    Revenue (Irish Tax and Customs) · Accessed 2026-08-21
  3. How do you complete a VAT 3 return?
    Revenue (Irish Tax and Customs) · Accessed 2026-08-21

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