The lender said it will allow customers who are already in receipt of pension income to take their mortgage to age 70.
However, from 23 November residential customers will not be able to take their mortgage past their intended retirement age if they are still working – this is the case even if the pension income is enough to afford the mortgage.
Any applications that have an element of lending into retirement need to be submitted by 21 November.
The lender said if the customer’s retirement age does not look realistic based on their profession, underwriters may ask for more information.
NatWest said it had made the decision as a “responsible lender”.