They will need to do this before November 30 this year and inform HM Revenues and Customs (HMRC) of their new details so that their payments aren’t delayed.
After this date, HMRC will stop paying Child Benefit, Guardian’s Allowance and Tax Credits into Post Office card accounts.
If customers already have an alternative bank account, they can contact HMRC now to change their details.
If they do not have an alternative account, they will need to set up a bank, building society or credit union account straight away in order to receive their money.
Failing to do so on time, could leave them without access to much needed cash.
READ MORE: Skipton offers 3.5 percent interest rate to compete with inflation
Meanwhile, Post Office customers who have other DWP benefits paid into their accounts like Universal Credit or Pension Credit do not need to worry as much.
The deadline for these customers to switch to an alternative payment account has been extended until November 2022.
Minister for Pensions, Guy Opperman, said: “Whilst the vast majority of pensions and benefits are paid directly into peoples’ bank accounts, some people prefer to collect their payments over the counter at their local Post Office.
“This extra time means we can support our most vulnerable customers to move to the payment method that will suit them best – even if that means making sure they can still get cash via the Post Office using a card from the new Payment Exception Service.”
Who qualifies for Child Benefit and Tax Credits?
Child Benefit is paid to eligible parents or carers who are responsible for a child under 16.
They will also receive this benefit if they have a child under 20 living at home, who is in full-time non-advanced education or approved training.
Parents or carers receiving Child Benefit and who also have an income over £50,000 may have to pay the High Income Child Benefit Charge via an annual Self Assessment tax return.
This is also true if they earn less than this amount but their partner earns more.
Meanwhile, people might receive Tax Credits if they are on a low income.
There are two types: Child Tax Credit paid to families with children and Working Tax Credit, paid to people in work on lower incomes.
More than 70 percent of families on Tax Credits are in work.
Their purpose is to help families on lower pay make ends meet.