Thousands of people on universal credit will not be paid over the festive season or will get a reduced payment.
About 67,000 people who work and are paid weekly will be hit, the Department of Work and Pensions says. Some will have to reapply for the benefit.
That is because there are five paydays that month, so their monthly income will be too high to qualify – the benefit is based on a calendar month.
The government says the benefit anticipates people’s circumstances.
Universal credit merges six benefits for working-age people into one new payment, which is reduced gradually as you earn more.
The Department for Work and Pensions warns on its website that people who are paid five times in a month may have an income that is too high to qualify for the benefit in that period.
It says people will be notified if this happens and told to reapply for the benefit the following month.
Other people who are paid fives times in a month but do not earn enough for universal credit to end will have their benefit reduced.
The government said the payments balance out, as claimants will receive more in the following month.
It said those who reapplied for the benefits would not have to submit new forms and would have their current claims restarted.
Universal credit is being rolled out across the UK in stages, but its implementation, particularly the six-week wait to receive the benefit, has caused controversy.
This week Labour leader Jeremy Corbyn told Prime Minister’s Questions that hundreds of families have been issued with eviction notices by a landlord concerned about the impact of universal credit.