Brokers will be able to produce mortgage illustrations and submit applications online for existing deals by 10:30pm today and the changes will come into force from tomorrow.
Within its core residential range, two and five-year fixed purchase and remortgage rates have been cut.
This includes its five-year fixed purchase rate at 75 per cent loan to value (LTV) falling by 0.3 per cent to 5.89 per cent.
The lender has also added a duo of two-year fixed purchase rates at 60 per cent LTV, with its no fee version coming to 6.54 per cent and its £995 fee version priced at 6.24 per cent.
The deals are also available for remortgage and come with £250 cashback.
Natwest had added a duo of five-year fixed rates at 60 per cent LTV, also for purchase and remortgage, priced at 5.74 per cent with a £995 product fee and its fee-free version is 5.89 per cent.
On the buy-to-let side, rates have increased by around 0.3 per cent. This applies to both purchase and remortgage.
An example includes its two-year fixed rate remortgage at 75 per cent LTV rising from 6.54 per cent to 6.84 per cent. It has no product fee and £250 cashback.
Within its existing customer range, the lender has added 34 switcher products split across fixed rates and tracker deals.
Two-year fixed rate switcher products start at 6.23 per cent at 60 per cent LTV with £995 product fee, with tracker products priced from 5.49 per cent at the same LTV tier and product fee.
Five-year fixed rate switcher products begin at 5.69 per cent at 60 per cent LTV with a £995 product fee.
Buy-to-let switcher products have gone up by around 0.2 per cent, such as its five-year fixed rate switcher at 75 per cent LTV with no fee rising from 5.89 per cent to 6.09 per cent.
