Up to 32,000 people have not received benefit payments in time for Christmas due to an administrative error.
Money for some jobseekers, low earners and pensioners was due to go into accounts today, but will not now arrive until December 27.
Those affected include new claimants, those owed arrears, and people awarded Social Fund budgeting loans for "essentials" such as clothes, rent and furniture.
The Department for Work and Pensions stressed that if individuals had contacted them by 5pm this evening the payment will have been rushed through within three hours.
"The vast majority of regular benefit payments have been made on time this Christmas," a spokesman said.
"However due to an administrative issue, a number of one-off or more irregular payments will now be paid on December 27 rather than the 24.
"We have procedures in place to ensure that anyone who has been affected by this and who contacted us today would have had their benefits paid, usually within three hours."
"We apologise for any inconvenience caused."
A total of 32,200 people claiming Jobseekers Allowance, Employment Support Allowance, Social Fund and certain categories of pension could have been hit by the delay, the spokesman said.