Tax relief decreases the amount of tax you pay to the government from your salary or freelance work. You will pay less tax to take account of the money you've already spent on electricity, water, gas, work equipment, transport, or uniforms.
Back in October, HMRC introduced a new microservice, which enables you to get the entire tax year’s claim regardless of how much you’ve actually spent at home, or whether you have receipts or not.
HMRC told MoneySavingExpert: “We recognise that the working-from-home situation is very fluid this year, so we're accepting claims for the full year’s expenses. Even if people have only worked from home for some of the year, to avoid needing to contact us if you have to work from home again”.