The lender now requires six months of bank statements, up from three months previously, as part of a refresh of criteria.
Brokers are “strongly” advised to discuss all self-employed cases with their BDM before submitting, Metro urged.
All businesses must have been trading for three years, and the lender uses an average of the last two years of salary and dividends or profit from partnerships and sole traders where “sustainability can be evidenced”.
A Metro Bank spokesperson said: “Self-employed applicants must now provide six months of business bank statements to us, when applying for a mortgage.
“This ensures that we can make a fair lending decision by assessing the ongoing sustainability of their business against recent trading levels.”
At the same time, Metro has suspended new broker registrations owing to demand until 2 November in order to process its existing pipeline of requests.