John Tulloch

I am trying to help an elderly friend (92) whose husband has recently died. She has received a Notice of Coding to advise that she owes £275 from a prior year. She has not completed a return for many years - her only income is a state pension of less than £6000 and interest below £1000. The coding says to visit HMRC but whilst the NI number is available I cannot see that she has ever registered for the Gov Gateway and I cannot trace a UTR. She has no verifiable ID such as a passport or driving licence. What can she do to get access to the information that HRMC are using to suggest underpaid tax?