The mortgage club will now be offering a 2.69% 2-year discounted rate mortgage at up to 60% loan to value.
The product has a £2,249 arrangement fee and a £250 booking fee and includes a free valuation for properties worth up to £1,000,000.
Ying Tan, managing director of The Buy to Let Business, said: “This incredibly low rate is ground-breaking for the buy-to-let sector.
“In all my years I have never seen such a low rate for buy-to-let and given a flat fee, free valuation and no early repayment charges it has blown me away!”
Carolyn Thornley-Yates, business development manager at Hinckley and Rugby Building Society, said: “Following a very strong start to the year we are looking to further increase application levels by offering this market-leading exclusive product to The Buy to Let Business.
“We are sure that landlords with at least 40% equity in the property will appreciate the very low charging rate, flat fee structure and free valuation.”