The Society's 2- year fixed rate mortgage has been cut from 2.19% to 1.99% and the 2-year fixed rate mortgage has fallen from 2.74% to 2.59%.
Richard Barker, product manager at Norwich & Peterborough, said: "Our low-fee mortgages have been proving especially popular with borrowers in recent months.
"In addition to best buy rates, these latest fixed rate deals come with incentives such as a free valuation and either free legal assistance or £200 cashback."
Each mortgage is available for loans up to 65% loan to value and has a product fee of £295.
