As a result of the increase, the total number of completions reached 2,363 last month.
Lending totalled £104.3m in June, representing a £14.3m increase on May 2021.
Average completion times were at 17.6 days, 3.8 days slower than the month before.
The majority of products were provided under 85% loan-to-value (LTV) at 84.73%.
The most popular reason for taking out a loan was consolidation at 45.89%. This was followed by consolidation and home improvements at 26.61%.
Matt Tristram, managing director or Loans Warehouse, said: “With freedom day approaching the second charge lending market has now officially hit pre-pandemic levels of lending and surpassed the £100m barrier
“With figures reported directly to the Loans Warehouse Secured Loan Index in June from multiple lenders, second charge lending totalled £104.3m in June 2021 – a post pandemic high.
“Lending increased 16% month-on-month and highlighted an incredible 365% record breaking year-on-year increase but let’s remember, this was one of the pandemic lows for second charge lending.
“A more realistic comparison would be lending figures from June 2019 which incredibly were all but identical to June 2021 with £105m reported by the FLA.
“This is also a landmark month with Optimum Credit posting lending figures of £37.9m which is believed to be the most lent by a single lender since the Credit Crunch of 2006!
“The increased lending did impact completion times with the average time to complete a second charge increasing to 17 days.
“In the year to date we have now recorded £493 in second charge lending and monthly new lending figures continue to improve.”