reclaiming overpaid tax from past years

worn_out

A friend of mine (retired) with just a state pension but some savings interest has had tax deducted from the interest for past 4 years. There is enough unused personal allowance left for non of this tax to be deducted..although accepting a form 85 should have been filled in previously.
So..although not massive amounts..about £400 in total..how do we go about reclaiming these past 4 years ?
We don't need a tax accountant I'm sure as there's nothing complicated, I hope ..Do we just get 4 copies of the R50 form filled in (one for each year) and send them off to HMRC ? Do documents need to be sent or are we on trust ? (we do have the documents).
Any advice much appreciated..thank you

booksurr

google it! eg: "reclaim tax on on interest"

Form R40, 4 years:
https://www.gov.uk/apply-tax-free-interest-on-savings/how-much-tax-you-pay

https://www.gov.uk/apply-tax-free-interest-on-savings/previous-tax-years

worn_out

thanks for that..i asked the wrong question on google and it led me to a form p50 !!!..