Amending Tax Return

Hi, I submitted my tax return a few weeks ago, but having spoken to an accountant I realised the advice I had previously been given was incorrect and need to make substantial changes to my return. How do I go about doing this? And what's the deadline for submitting them? Thank you!

Hi,

To amend your return, log on to your personal tax account, and click on the Self Assessment tile. You should be able to amend and update your return from where you initially filed it. You can correct a tax return within 12 months of the Self Assessment deadline for the year you filed. You can see more information here:

If you need to change your return

Thank you.

Hi, needed some advice, so the last 2 financial years i have done my returns via an accountant and this year i though id save money by doing it myself. And i guess i should’ve got my accountant to do it as ive now got an eye watering tax bill as ive declared my income way way more than i thought it was. I should’ve done Apr 23 to Apr 24. But i accidentally included income all the way up to this month in the calculation. Meaning i did 19 months worth instead of 12 months. Am i able to amend it simply online? Will i need to send in evidence as i will be putting in my actual amount of income? In case HMRC think im trying to lower it on purpose. Very anxious and confused. Thank you for any advice.