The launch will be divided across two dates. It will be available through mortgage brokers from tomorrow and customers making direct applications will be able to apply from 13 September.
The term will be an option for residential capital repayment and buy-to-let mortgages.
Interest-only residential applications remain capped at a 25-year maximum term. This includes part and part mortgages.
Second home applications and additional borrowing also qualify for the maximum mortgage term of 40 years.
Andrew Matson, head of mortgages at HSBC UK, said: “We know that home ownership is a key life ambition for many people, but affordability can be an issue. We are delighted to introduce our first ever 40-year mortgage term to our customers. This move underscores our commitment to supporting aspiring homeowners in their journey onto the housing ladder.
“By extending the mortgage term we aim to help make mortgages more manageable with lower monthly repayments and homeownership a reality for our customers.”
According to Criteria Brain, maximum mortgage terms range from 35 to 50 years for residential applications, with the majority falling at the 40-year mark.
Of the lenders listed, 52 offer a 40-year maximum term, 17 offer 35 years, one offers 50 years and another offers 41 years.