Comment by teamonkey

I'm in the pay bracket requiring annual self assessment and 10 minutes is probably too generous, purely because you log in to your SA account and the PAYE section from your employer is already pre-filled. You don't need to look at your pay slips, HMRC already has all the info from your employer and literally all you need to do is have a cursory glance whether the numbers look right then click confirm few times and submit at the end.

Obviously very different if you're self employed or have income mostly from investments or properties, but the you have an accountant to do it for you.

I've been doing UK self assessment tax returns every year for over 15 years. It really does just take 10-15 mins for people that have one job (as an employee) and typical investments - savings accounts, shares, etc.

The income numbers are already there and if I want to check it's easy: my employer gives me a form with the same numbers in the same numbered boxes. I just need to specify how much income I had from bank interest.

The tax witholding system usually works as well - the main exception being straight after starting work for the first time or changing jobs, when you can have a temporary code. In these cases I just called HMRC and told them what was going on. The employer gives my pay numbers to HMRC and HMRC give my employer a tax code that determines how much to withhold each month.