Customers are reporting receiving letters out of the blue about the compensation, with many assuming it’s a scam – but it’s not.

HSBC Group, which owns all four brands, says an internal review uncovered instances where customers in arrears on mortgages, loans, credit cards and overdrafts hadn’t received the quality of service expected between 2010 and 2019.

Examples of bad practice included poorly worded letters that didn’t engage customers who might have been struggling.

As a result, affected borrowers will be sent cheques in the post of between £25 and £100 depending on the level of poor service. The payment is a ‘goodwill payment’, not a refund.

Cheques began being sent in late October with the last letters due to arrive by the end of March 2021.

The payouts could be made to all types of borrowers, from mortgages to personal loans, current accounts with overdrafts, and credit cards. HSBC is not saying how many customers are affected.

The banking group is contacting affected customers, including those who have since closed their accounts, directly.

A HSBC UK spokesperson told MoneySavingExpert.com: “We always strive to do the right thing by our customers. Regrettably, some historic cases where customers were in arrears at times fell short of this commitment. We are taking action to put that right and remediate customers who may have been impacted. Customers do not need to do anything.”