The two-year discounted standard variable rate (SVR) mortgage is available to first-time buyers and those remortgaging looking to borrow up to 65% of the value of the property.
The new 0.89% product matches the Yorkshire’s SVR at a discounted level of 3.85% for two years before reverting back to the SVR which is currently 4.74%.
Borrowers need to stump up a product fee of £1,495 or alternatively, Yorkshire also offers a £995 product fee on its 1.05% mortgage deal.
The mutual is also offering a joint-lowest fixed rate mortgage at 0.99% for borrowers with a 40% deposit.
It comes just a couple of days after digital-only Atom Bank pulled its record low five-year mortgage deal priced at 1.29%.
Commentators are suggesting a rate war has started however, a Mortgage Solutions poll earlier this week revealed brokers divided despite the Atom rate launch.
The product is direct-to-consumer only and the mutual confirmed it has no plans to launch the rate to advisers. The lowest Accord Mortgages rate currently is a two-year tracker at 0.99%.
James Farrow, senior mortgage manager at Yorkshire Building Society, said: “We are very pleased to offer borrowers the lowest mortgage rate ever available.
“The cost of funding has fallen in recent weeks and as a financially strong building society with no external shareholders to satisfy we have the ability to pass this on to borrowers.”
Rachel Springall, finance expert at Moneyfacts, said: “It’s fantastic to see such low rates on offer from Yorkshire Building Society and the choice between variable or fixed deal will appeal to different types of borrowers.”