Its five-year fixed rate, which has a maximum loan to value (LTV) of 75 per cent, has been reduced from 2.6 per cent to 2.45 per cent.
The product is subject to an early repayment charge (ERC) of five per cent in the first year of the fixed rate period, which then goes down by one per cent each subsequent year thereafter.
The two-year fixed rate, which is available up to 75 per cent LTV, has a rate of 2.39 per cent. It has an ERC of two per cent in the first year and one per cent in the second.
Both products come with free standard valuation of up to £500,000 and has £500 cashback. Overpayment of 10 per cent a year are allowed in addition to £499 monthly overpayments allowed.
Those with a product term of five years or more have an interest coverage ratio of 145 per cent at a rate of 5 per cent, and for two-year product terms it has a rate of 5.5 per cent.
Franco Di Pietro, head of intermediary mortgages at Newcastle Building Society, said: “We’re delighted to reduce rates on our BTL products which include these competitive fee-assisted options for borrowers.
“They offer flexibility, competitive rates and a number of benefits, underpinned by our adaptable, nuanced approach to underwriting.”