Mobile operator easyMobile has notified its customers that the service will shut down on 13 December. About 80,000 customers are thought to be affected.
The mobile phone company was a joint venture between Stelios' easyGroup and Danish telco TDC. The latter company is behind the closure, as it has decided to withdraw from the UK market.
A statement has been released by easyMobile saying that it will refund any outstanding phone credit when the company closes.
The company has made an arrangement with the The Carphone Warehouse's Fresh Mobile service to transfer numbers and phones, if required.
It has also said it will unlock handsets and provide Porting Authorisation Codes (PAC), if nesessary, for transfer of a number to another operator.