Self-Correction: Fixing a Return You Already Filed
If you find a mistake in a return you've already filed, a missed expense, a wrongly entered revenue line, you don't have to wait for NAV to find it: you can fix it yourself through self-correction (önellenőrzés). This article covers when it's available, what it costs, and why fixing it yourself beats being caught.
When can you self-correct?
Self-correction is available when the base or amount of the reported tax (or budgetary support) in an already-filed return actually changes: for example, because you later found a cost receipt you hadn't included, or miscounted an item. If the mistake doesn't affect the tax base or amount (say, just a typo in a name or address), a simple data correction handles it: not self-correction.
Self-correction is available within the statute-of-limitations period: 5 years for most taxes, counted from the end of the calendar year the return should have been filed, the same window covered in the record-keeping article.
When can't you self-correct?
If NAV has already started an audit for that specific tax and period, self-correction isn't available from that point until the audit ends: the mistake gets resolved through the audit process instead. This is exactly why it's worth fixing something yourself as early as possible, before an audit beats you to it.
How much does self-correction cost?
If the correction results in less tax owed, or a refund, you don't owe any self-correction surcharge. A surcharge only applies when the correction reveals an additional payment obligation: meaning you originally owed more than what you reported and paid.
The self-correction surcharge is, for every calendar day, one 365th of the current central bank base rate: in 2026, currently (as of July 22, 2026) at a base rate of 5.75%, that's roughly 0.016% a day. The MNB's base rate can change more than once within a year, so always use the rate in effect on the day you file the self-correction. For a repeated self-correction of the same return, the rate is 1.5 times higher. Importantly, the self-correction surcharge is typically lower than late-payment interest (késedelmi pótlék), since the latter adds 5 percentage points to the base rate before dividing by 365.
Why is fixing it yourself worth it?
If NAV finds the same mistake during an audit, it can impose a default penalty (adóbírság) on top of the missing tax and late-payment interest: normally 50% of the tax shortfall, and up to 200% in more serious cases (concealed revenue, falsified documents). If you fix the mistake yourself, through self-correction, before NAV's audit starts, and pay the missing tax plus the self-correction surcharge, you're exempt from the default penalty entirely. Self-correction is therefore the cheapest way to resolve a mistake before it gets more expensive.
How do you file it?
Self-correction is filed on the same return form (or its self-correction variant/section) as the original return: marked as a self-correction, with the correct data, and with the self-correction surcharge, if any, calculated and declared separately.
This article is for general information only and does not constitute tax advice. Source: the Rules of Taxation Act, 2017. évi CL. törvény (net.jogtar.hu), and NAV's penalty-practice guidance no. 3006/2018.
Last updated: July 31, 2026.