Hey there, UK taxpayers! So, you’ve missed the tax return deadline – oops! Whether you’re a self-employed tradie, a landlord, or just someone with a side hustle, missing that all-important Self Assessment deadline can feel like stepping on a financial Lego brick. But don’t panic just yet – let’s break down what happens next, chuck in some real numbers, and figure out what this means for you.

If you're a UK taxpayer who needs to file a Self Assessment tax return, missing the deadline can come with serious consequences. HM Revenue and Customs (HMRC) has strict rules on when tax returns and payments are due, and failure to meet these deadlines can result in automatic penalties and interest charges.

In this section, we'll break down the exact deadlines you need to meet, explain why timely filing is crucial, and look at how many people actually get penalized each year.