The increase in maximum LTV for buy-to-let mortgages, from 75% to 80%, includes purchase and remortgage products for first-time and experienced landlords, as well as let-to-buy.
The same criteria will apply to those products available through the current limited company range, which is being piloted.
Applications for products of less than five years above 75% LTV will be stressed at 5.99% or pay rate plus 2%, whichever is the higher.
For terms of five years or more the stress rate is 4.99%.
The maximum loan per property is £350,000.
HMOs at 75%
Two-year fixed rate 80% LTV products start at 2.99% with a 2% fee and 3.99% rate with no fee and are available for purchase and remortgage.
Meanwhile, five-year fixed rate products start at 3.59% with a 2% fee and 4.19% rate with no fee.
In addition, the maximum LTV for buy-to-let mortgages on houses of multiple occupation (HMOs) will increase from 65% to 75%.
Nationwide director of specialist lending Paul Wootton said: “TMW is extending its range of mortgage products to include loans at up to 80% LTV to give greater choice and more options for landlords, including those taking out new buy-to-let mortgages and those looking to refinance existing borrowing.
“TMW is entering an established part of the market to offer a range of competitive rates to landlords working to manage their costs, including for those with smaller amounts of capital invested,” he added.