More than 85,000 Universal Credit claimants could see their payments rise from Monday onwards after the Department for Work and Pensions addressed an "unfair" loophole that's cost people thousands of pounds.
From November 16, claimants who get paid their monthly salary twice in a calendar month by their employer will not be penalised.
The changes don't apply to people paid weekly, fortnightly or 4-weekly.
Under the old rules, workers who were paid a monthly salary twice in an assessment period were flagged as 'over-earning' on the DWP's systems. This means their following payment was reduced - sometimes to zero - to reflect their higher income.
But in the majority of cases, they're not over-earning at all.
Often, it's because their employer paid them on the first or last working day or they received a late or early payment because of a bank holiday.
The flaw often leaves vulnerable families without any benefits for a whole month. In the majority of cases, a portion of the "double payment" will docked from their next payment because of the taper rate which is set at 63p for every ￡1.
Mum Danielle said she had experienced significant fluctuations in her benefit income because of a 'clash' between her monthly paydays and the DWP's fixed monthly universal credit assessment periods.
Between them, the four mothers fell into rent arrears, defaulted on council tax, incurred bank overdraft charges, borrowed money and even become reliant on food banks to make ends meet.
The judge concluded that the "irrational and unfair" system pushed them into poverty and forced them to rely on food banks.
The DWP was ordered to fix the flaw - and has now confirmed the new rules will come into force in November.
It said that from November 16, the benefits system will only register one payment for every assessment period to stop anyone losing out.
But the adjustment won't be automatic and needs the person affected to tell the DWP, through a post on their UC journal or a telephone call.
Child Poverty Action Group explained: "To get a payment adjusted as quickly as possible, the person affected should alert the DWP as soon as they see from their UC payment statement that (a) the UC amount is lower than expected and (b) the earnings reported by the employer as recorded on the statement is the sum of two months’ earnings. Don’t wait until the UC is actually paid."
It added: "The person affected should say that: they are in regular monthly paid employment; two wages have been included in the one assessment period they want one of those wages to be reallocated to another assessment period under regulation 61(6) Universal Credit Regulations 2013; and upload the wage slips for both wages which have been included in the one assessment period as evidence."
Peter Tutton, head of policy at StepChange welcomed the change but added: "It is also important DWP continues to seek ways to stabilise payments for those who face similar problems, such as those who are paid weekly or bi-weekly or have an irregular income."
Minister for welfare delivery, Will Quince, said: "Universal Credit is a flexible benefit, and we continue to make changes and improvements to make sure people have the best experience possible.
"This change will give stability to people if they’re paid two pay cheques in a single assessment period, by ensuring that their Universal Credit payments remain consistent."