The lender has cut rates at 65% and 75% LTV.
The Mortgage Works (TMW) has reduced rates across its 2 and 5-year buy-to-let product ranges.
At 75% LTV the 2-year fix has seen its rate drop from 2.19% to 1.74% while the 5-year fix is now priced at 2.14%, down from 2.24%.
At 65% LTV the 2-year fix has been cut from 2.34% to 1.89%.
These products come with a free valuation, £250 cashback and include a £995 fee.
Henry Jordan, director of mortgages at Nationwide, said:“TMW offers landlords a broad range of options to meet their varying needs, but it is important that these remain attractive when landlords are choosing their mortgage.
“That is why we are further increasing the competitiveness of our 2 and 5-year rates.
“By making these reductions, we are also continuing our support for landlords looking to manage their finances through fixed rates.”
Within the Houses in Multiple Occupation range at 65% LTV, the 2-year fix has had its rate reduced from 3.19% to 2.49% and comes with a free valuation.
For those with a large portfolio, the 2-year fixed rate at 75% LTV was cut to 2.59%, from 2.79%.
This comes with a £995 fee and includes a free valuation and £250 cashback.