So-called “marathon mortgages” are fast becoming the norm, new analysis suggests, as two-thirds of borrowers aged under 30 have terms of between 30 and 40 years.

The overpayment app Sprive found 66% of borrowers under 30 have mortgage terms of this length, compared with 42% of those aged between 30 and 39 and just 6% of homeowners aged 40 to 49.

As a result, homeowners under 30 are on course to pay off their mortgage at an average age of 59.

The analysis, based on more than 190,000 homeowners, also found younger borrowers face higher average mortgage rates.

Under-30s pay an average rate of 4.5%, compared with 3.89% among those aged 40 to 49.

Average monthly repayments remain above £1,000 across all age groups, Sprive found.

Under-30s pay an average of £1,008 a month, rising to £1,138 for those aged 40 to 49 before falling among older homeowners.

Sprive chief executive Jinesh Vohra says: “Longer mortgage terms have become the price many younger buyers have to pay to get onto the property ladder.

“Spreading repayments over 30 or even 40 years can make monthly payments affordable, but it also means paying interest for much longer and staying in debt well into later life.

“The good news is that there are ways to cut the debt; making overpayments, even relatively small ones, can shave years off the mortgage and save tens of thousands of pounds in interest.

“Many people don’t realise how much difference regular overpayments can make.”