The Post Office has launched a five-year fixed-rate mortgage at 3.55% with no arrangement fees.
You will need a hefty 25% deposit to take advantage of this deal. There is also free valuation and legal fees for borrowers re-mortgaging.
Next best is Chelsea Building Society at 3.34% but this comes with a £1,495 fee.
You need to be borrowing £127,000 or more for the Chelsea loan to work out less expensive.