Help in mortgage interest payments was paid by DWP about 7 years ago and assume it is still the case. Housing Benefit (HB, now making up part of the living allowance of Universal Credit for some) can be awarded to a tenant renting privately but the govt will only pay an amount based on the claimants needs not the size of house they rent. In other words, a couple with one child would be eligible to a 2 bed Local Housing Allowance (LHA) rate but if they rented a 3 bed house they would see a shortfall between rent charged and housing benefit paid (known generally as the “bedroom tax” when a tenant rents a council house). Also, private landlords charge calendar monthly but HB paid 4 weekly so over a 12 month period, a private tenant would be charged 12 times but recieve 13 HB payments over the same period. In some cases this method of payment effectively ‘pays back’ the tenant the top ups they’ve paid monthly over the year.
I hope that makes sense, I easily can go off on a tangent/waffle on about this sort of thing! Hope the info helps any potential readers and best of luck to anyone struggling at the moment.