Mortgage approvals increased by 6.4 per cent from April to May, reaching 66,479, the latest figures from e.surv reveal.
Approvals were also up marginally year-on-year with 0.5 per cent more mortgages agreed compared to to May 2017.
The surveying firm says that first-time buyers and borrowers with small deposits saw their share of lending increase month on month.
First-time buyers and others with small deposits saw their share of the market increase month-on-month.
Some 22.4 per cent of the overall market went to these borrowers during May, significantly higher than the 20.2 per cent rate found in April.
There was a wide variation between the regions of the UK, with some areas seeing a much higher proportion of small deposit borrowers.
In Northern Ireland 35.7 per cent of all loans went to this part of the market while in London this ratio was 13.8 per cent.
The surveyor argues that activity may have been boosted by the rumours that the Bank of England would increase the base rate in May.
While the central bank later chose not to increase the base rate, the speculation may have prompted some people to consider the mortgage options and lock in a low mortgage rate, it says.
Director Richard Sexton says: “There was strong growth in the mortgage market in May, with approvals rising significantly compared to April.
“Mortgages are at the forefront of the national conversation, with many people assessing their options and looking to fix in this rising interest rate environment.
“While the base rate may have stayed at 0.5 per cent in May, speculation continues about the next increase, which appears to be coming sooner rather than later.”