The claims relate to TSB’s subsidiary Whistletree, which was set up in 2016 to manage Northern Rock mortgages acquired from the government’s holding firm UK Asset Resolution (UKAR).

TSB purchased the £3.3bn of mortgages held by approximately 200 homeowners. 

It has been claimed that the mortgage holders have overpaid £50,000 in interest as they allege Whistletree has almost doubled the rates since the loans were bought. The group also claim that until recently, borrowers were not allowed to transfer onto TSB rates. 

Law firm Harcus Parker is bringing the case to the High Court this autumn and has said up to 27,000 customers could potentially make a claim. 

‘Devastating impact on the lives of homeowners’

Matthew Patching, senior associate at Harcus Parker, said: “Our clients have been treated terribly by TSB: they have been charged interest on their mortgages at rates significantly higher than those charged to other similar customers at the same bank.   

“This has had a real and devastating impact on the lives of homeowners who, other than happening to take out a mortgage with Northern Rock prior to the global financial crisis, are often identical to large numbers of TSB’s other customers.” 

‘Treat customers fairly’

A spokesperson for TSB said: “TSB is aware of potential action proposed by Harcus Parker and will robustly defend its position.  

“We are committed to treating our Whistletree customers fairly. TSB took ownership of the Whistletree mortgages in 2016 and subsequently created access to product transfers for customers who did not previously have access to them.

“Since then, over two-thirds of Whistletree customers have either transferred to a new Whistletree product or closed their mortgage with Whistletree. We write to customers twice a year to remind them about the opportunity to switch.”