What happens if I discover I made an error on a previous Malta tax return?

If you've identified a genuine error in a previously filed tax return, the generally appropriate and advisable course of action is to proactively correct this with the Commissioner for Revenue rather than simply leaving the error uncorrected, since Maltese tax administration under the Income Tax Act, Chapter 123 of the Laws of Malta, generally treats voluntary, proactive disclosure of an error considerably more favourably than a situation where an underreporting is later discovered through an audit or investigation, potentially resulting in a meaningfully different outcome regarding any applicable penalties or interest. The specific process for correcting a previous filing would generally involve properly documenting the actual error and the corrected figures, and formally notifying the Commissioner for Revenue of the correction, along with paying any additional tax that becomes due as a result along with applicable interest, though the exact procedural mechanism and any potential penalty implications can depend on the specific nature and materiality of the error and how much time has passed since the original filing. Given both the genuine value of properly and correctly addressing this kind of disclosure, and the potential complexity in accurately recalculating your correct liability and properly navigating the correction process, it would be strongly advisable to engage an accountant or tax advisor to help you prepare and submit the correction properly rather than attempting to navigate this yourself.