Missed the 30-day window after crossing your threshold? Here’s what Revenue does next and how to limit the damage.
Last updated: June 2026
Revenue backdates your effective registration date to when you should have registered, and you owe VAT on your taxable sales from that date forward, whether or not you actually charged customers VAT at the time. If you didn’t add VAT to your invoices during the period you were late, you generally still owe Revenue that amount out of your own revenue.
Beyond the backdated VAT itself, Revenue can apply penalties for failure to register on time, plus statutory interest calculated daily on any outstanding amount from when it was originally due. The exact penalty depends on the circumstances, including whether the failure was deliberate or a genuine oversight.
Not automatically — Revenue has discretion, especially for genuine, promptly self-disclosed mistakes, though VAT owed and interest generally still apply.
Generally yes. Your registration is backdated, and you’re liable for VAT on sales made from that date, meaning you effectively absorb it unless you separately invoice customers.
A formal process for proactively correcting tax errors with Revenue, which can result in reduced penalties compared to Revenue discovering the error itself during an audit.
Yes, you can request a review of Revenue’s decision and, if unsuccessful, appeal through the Tax Appeals Commission process.
Track your rolling 12-month taxable turnover regularly — our VAT threshold checker can help you monitor this.
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