Claiming COVID-19 relief for previous tax years if I did not complete a self-assement

I want to claim tax relief/a tax refund for working from home in the 2019/20 and 20/21 tax years. I did not complete a self-assessment tax return for those years as I was not self-employed then (I was working for an employer). How can I claim back this overpayment on my self-assessment return for 22/23?

Hi JLaw,

You would not claim this on Self Assessment Tax return. 
You need to make a claim for the individual years.
You can do this by submitting a P87 for each year:
Guidance here: 
Claim Income Tax relief for your employment expenses (P87)

Thank you.