A technical problem has forced the Northern Rock bank to postpone the launch of its £99 mortgage application fee.

The new, lower fee was launched for customers applying for tracker, fixed rate and buy-to-let mortgages on Monday, but then had to be withdrawn due to a system error.

“We launched on Monday and we found that there was a systems issue that will be resolved. It is something that is being addressed as a priority,” said a spokesperson for the bank. He declined to provide further information on the nature of the systems error.

Northern Rock has said it will honour the £99 fee for anyone who applied for a mortgage on Monday.

While the technical issue is being resolved, customers will be charged the previous rate of £250. Those who applied for mortgages after Monday will also be charged the higher rate.

Northern Rock has recently implemented email security software from supplier Symantec, in order to meet changing regulatory requirements.

Separately, the bank announced in June plans to cut 650 jobs by the end of the year, and was not able to say if IT roles would be safe.