New 2-year mortgage rates include 1.99% with early repayment charges (ERCs), and 2.49% without ERCs.
For 3-year terms, rates include 2.29% (with ERCs) and 2.69% (without ERCs).
Specific products for larger loans of £1,000,001 to £2m are available, and arrangement fees have been reduced, with the society introducing set application and completion fees.
These include a £100 application or booking fee, which applies to all products, with arrangement fees of £800 up to £1m and £3,000 up to £2m
Holiday let, holiday home and second home products are now combined, with new loan-to-values (LTVs) of 80% and 75%, and the option for no ERCs.
As well as this, mortgage products are available for purchase, remortgage and capital raising.
Harpenden will also accept different types of employment, including employed, self-employed and retired, and will consider a range of additional incomes, such as those from a pension, drawings, dividends, rental, investment or trust income, and maintenance.
Emily Smith, head of distribution and marketing at Harpenden Building Society, said: “We are pleased to be offering reduced rates in what is a very buoyant mortgage market.
“In addition to great rates and features, our mortgages continue to be individually underwritten, all with the aim to get the mortgage application approved, however complex.
“These are exciting times for the Harpenden and give a flavour of the positive changes to come.”