The pair of Help to Buy deals are exclusively for first-time buyers and come with no product fee, free valuation and £500 cashback.
Both are available at 75 per cent LTV with the two-year deal at 1.85 per cent and the five year version at 1.99 per cent.
On its standard remortgage and purchase range, five deals have been trimmed at 60 per cent and 75 per cent LTVs.
The five-year fix at 60 per cent LTV with £999 product fee has been cut by 0.16 per cent to 1.49 per cent, while the ten-year fix at 75 per cent LTV with £999 product fee has been cut by 0.15 per cent to 2.34 per cent.
Four large loan products, for purchase and remortgage up to £3m, have had their rates cut.
The largest of these is the 60 per cent LTV five-year fix with £2,499 product fee cut by 0.2 per cent to 1.69 per cent.
The lender has also increased rates on two of its 95 per cent loan to value (LTV) fixes by 0.1 per cent – with the two-year version rising to 2.99 per cent and the five-year up to 3.34 per cent.
The changes come into effect on 22 October.