These changes have been made as a direct result from received feedback.
Natwest Intermediary Solutions is making changes to its lending criteria following a review of its lending policies and key market segments.
The minimum income requirement from at least one applicant for a residential interest only mortgage is being reduced from £100,000 to £75,000.
The maximum loan-to-value (LTV) for a residential mortgage on a new-build house is being increased from 80% - 85%.
From 12 May, the loan to income maximums for loans of over £500,000 will be raised for all LTV bands up to 90% to match the current limits for loans of £500,000 or less.
Graham Felstead, head of intermediary mortgages, said: “We are keen to continue the fantastic growth in lending we have enjoyed over the past three or four years.
“These carefully considered changes to our criteria ensure we still continue to lend responsibly while providing brokers with more flexibility to recommend NatWest to their customers.
“Our business is grounded in the dialogue we hold regularly with representatives from broker firms.
The three enhancements we have made are a direct result from the feedback we received, so I am delighted that we have been able to deliver on them.”