AJ Bell estimated that the cap would now be £562,500 if it had risen in line with house price inflation.
Laura Suter, of AJ Bell, added: “Many aspiring homebuyers will have signed up to the accounts years ago, not realising that it would take so long to get on the property ladder and that they might fall foul of the property limit in the future.
“What makes the situation more galling for first-time buyers who have been priced out of using the Lifetime ISA is that they now face losing some of their own money when they withdraw their cash from the accounts, thanks to the onerous withdrawal penalty.”
The stamp duty limit for first-time buyers was raised to £625,000 last year, which Ms Suter said left a “stark gap” between it and the LISA limit.
Someone who opened a LISA in the first year they were available and saved the maximum amount of £4,000 a year would have been given £5,000 in government cash – and would have a pot of £35,000 today, Ms Suter said.
But should such a saver breach the £450,000 limit when buying a home, they would lose £2,250 of their money.
The Telegraph understands that Chancellor Jeremy Hunt is considering raising the Lifetime Isa limit as part of his Autumn statement later this month.
Ms Suter said: “A move to increase the property threshold wouldn’t cost the government huge sums and would allow many more first-time buyers to benefit from the Lifetime ISA bonus boosting their deposit savings.
“If Prime Minister Rishi Sunak is looking for ways to win votes that won’t cost the earth, this is one.”
Martin Lewis has called on the Treasury to overhaul the LISA scheme so that an account holder purchasing a first-time property for more than the maximum house price would not have to pay a withdrawal penalty.
Instead they would lose the Government’s 25pc bonus, but get their own money and interest back.
He added: “Many who have opened Lifetime Isas with government encouragement now have not only a dead duck product – where they won’t get the promised 25pc boost – but one with a poisoned beak because they’re fined to get their money out.
“The fine was originally put in place to stop people using LISAs for purposes other than what they were intended for. House-buyers aren’t doing that, so they shouldn’t be penalised; they should at least get back what they put in.”
