A standoff between banks and the government means that loan applicants could be rejected if they receive the new payment.

Thousands – perhaps even millions – of people could have trouble obtaining a mortgage because of problems with the way the government’s universal credit system and banks and building societies “talk” to each other.

A Guardian Money investigation into the difficulties experienced by a homebuyer living in one of the areas chosen to test the new benefit has revealed that some recipients could be at risk of being turned down for a mortgage. Some lenders are saying they will not accept universal credit at all when calculating how much they will lend, while others have apparently not amended their IT systems to deal with it – leading to problems and delays. On its published list of acceptable income types, Halifax’s website simply gives a blunt “no”.

Many lenders do accept it in some situations, but a key problem is that the most up-to-date version of universal credit is fully online and paperwork-free. Many banks and building societies, however, still insist on an official “hard copy” letter detailing how much benefit someone is getting. In essence, it’s an “old tech v new tech” clash.