The 20-Day Rule for Corporate Tax Errors

The legal home of the rule is Article 10 of Federal Decree-Law No. 28 of 2022 on Tax Procedures, as amended. The article obliges the registrant to notify the Authority of errors in tax returns, tax assessments, or refund claims using the voluntary disclosure form, within 20 business days of becoming aware of the error. Note the three objects the article covers: it is not only returns. An error in an assessment the FTA issued to you, or in a refund claim you submitted, triggers the same duty and the same clock.

Missing the deadline does not cancel the duty to disclose — it adds a penalty to it. No fixed penalty attaches to a disclosure filed after the 20-business-day window, but the 1% monthly voluntary disclosure penalty on the tax difference runs until the disclosure is filed (Cabinet Decision No. 40 of 2017 as amended; No. 75 of 2023 for corporate tax), and the tax itself stays payable. Confirm the current figures on tax.gov.ae rather than relying on second-hand numbers. The far worse outcome is not disclosing at all: an error the FTA discovers first is assessed with the full penalty stack, and the voluntary route is closed for that error.

Article 10 of Federal Decree-Law No. 28 of 2022 on Tax Procedures (as amended) requires a voluntary disclosure where a tax return, tax assessment, or refund claim understated the tax due, and Article 10 of Cabinet Decision No. 74 of 2023 sets the deadline: within 20 business days of becoming aware where the understatement exceeds AED 10,000; an error of AED 10,000 or less is corrected in the next tax return instead. The clock starts on awareness, not on the date the error happened: an invoice mistake from two years ago only starts the clock on the day you actually discover it. Business days are UAE working days, so Fridays, Saturdays, Sundays, and UAE public holidays do not count. In practice, the single most important habit is writing down the discovery date the day it happens — an internal memo or email recording what was found, by whom, and when — because that date is what the 20-day count is measured against if the FTA ever asks.

Three different tools fix three different problems, and using the wrong one wastes weeks. An amendment corrects a return that has not yet been filed or is still within its filing window — if you spot the mistake before submitting, just file the return correctly. A voluntary disclosure corrects a return, assessment, or refund claim that is already filed and wrong: you tell the FTA about your own error within 20 business days of discovering it (where it understated tax by more than AED 10,000; smaller errors go in the next return). A reconsideration challenges an FTA decision you disagree with — an assessment, a penalty, a rejected refund — and it runs on a completely separate 40-business-day clock from the date you are notified of the decision, under Article 29 of Federal Decree-Law No. 28 of 2022. Filing a reconsideration does not correct your return, and filing a disclosure does not challenge a decision. Pick the tool that matches your situation before the shorter of the two clocks runs out.