Some 19,400 Milton Keynes people who claim tax credits to top up their income have been warned they only have until July 31 to renew their claims.
If they fail to act, they are being warned that payments might stop.
Across Buckinghamshire there are some 43,600 tax credits claimants and Nick Lodge, HMRC’s director general of benefits and credits has asked people to renew immediately.
He said: “The sooner they do, the sooner we can check their payments and avoid paying too little, or too much money, which they then have to pay back.”
Tax credits renewal packs have been sent to about 5.8 million people across the country since April. Last year more than 80 per cent of claimants renewed by the July 31 deadline.
HMRC asks claimants to check the accuracy of the information in their packs, and to tell the department about any changes to circumstances that they haven’t already reported. These include altered working hours, childcare costs or pay. They must also tell HMRC whether they are single or living with a partner.
Claimants can renew by calling the Tax Credit helpline - 0345 300 3900, or post their renewal to the address in the pack that was sent to them.
More details from www.hmrc.gov.uk/taxcredits/keep-up-to-date/renew-claim/index.htm