Meanwhile, instruction volumes decreased by 16.1% over the same timeframe.
The overall cancellation rate decreased by 0.3% to 6.47% and pipeline cases fell by 0.7% in April.
The average monthly payment decrease for those who remortgaged in January was £195.
A total of 53% of borrowers increased their loan size and 53% of those who remortgaged took out a 5-year fixed rate product, which was the most popular product length.
An estimated 31% of remortgagers’ primary aim when remortgaging was to release equity from their property.
The average loan increase post remortgage was £21,049, whilst the average loan decrease post remortgage was £10,260.
Nick Chadbourne, chief executive of LMS, said: “Despite the drop in instructions, remortgage activity levels remained healthy through April with completions up 17.1% and fewer cancellations across the month.
“The industry continues to work through the backlog to meet sustained demand, buoyed by the attractive repayment rates offered by lenders as they continue to compete for business.
“On the other side of the market, HMRC figures released in May reveal a monthly drop of 35% in residential transactions, yet purchase activity remains at the highest level we’ve seen in April since 2007.
“This heightened demand is expected to persist, fuelled by a combination of the SDLT extension, continued competitive mortgage rates and the government’s mortgage guarantee scheme which launched in April.
“Looking ahead the shift between purchase and remo is likely to change.
“As borrowers rush to complete purchases ahead of the reintroduction of the SDLT in July, there is an expectation that activity will slow following the deadline, perhaps sharply.
“A decline in purchase activity could lead to a growth in remortgage enquires as borrowers decide to stay put until market conditions steady.
“A decrease in purchase activity will reduce pressure on the mortgage market, freeing up industry capacity for remortgage business and contributing to a healthy pipeline in H2 this year.”