ALMOST £300m was invested across Innovative Finance ISAs (IFISA) in the previous tax year, HMRC data reveals.
The latest ISA statistics from the taxman shows £290m of subscriptions in IFISA for the 2017/2018 tax year across 31,000 accounts.
P2P lenders saved £9,355 on average.
Zopa revealed it received more than £150m in its IFISA during the previous tax year.
“These figures are further evidence of that fact that people want a reliable alternative to lower return cash savings products or the volatility associated with investing on the stock market,” Natasha Wear, head of investment products at Zopa, said.
“Investing in loans through a robust peer-to-peer platform can be a great middle ground, especially when the returns are tax free as with the IFISA.”
A RateSetter spokesman said the popularity of its IFISA has “exceeded expectations.”
“Since launch in February, investors have subscribed £130m and this continues to grow,” a RateSetter statement said.
“With cash ISAs unable to even keep up with inflation, the RateSetter ISA has quickly become a real option for people seeking better returns in exchange for accepting some risk.”
The overall figures could be higher as a note in HMRC’s report says it does not yet hold full information from all P2P providers.
This is still a big increase on the first year of the IFISA in 2016/2017 when there were fewer tax-free wrappers from P2P lenders on the market.
Only a few P2P lenders such as Abundance and Crowdstacker offered IFISAs in its first year, but bigger brands such as Zopa, RateSetter and Funding Circle had their product available for the 2017/2018 ISA allowance.
However, the document shows HMRC has revised the figures for the first year of the product.
Last year it claimed there were £17m IFISA subscriptions across 2,000 accounts.
But this has now been revised to £36m of subscriptions across 5,000 accounts for the 2016/2017 tax year.
The revision follows queries from P2P lenders last year over the reliability of the IFISA statistics.
The increase in IFISA accounts comes as the number of cash ISA openings fell by 8.2 per cent to 7.7m, with £39.8bn subscribed.
There was a 9.5 per cent increase in stocks and shares ISA accounts to 2.8m, with an inflow of £28.7bn.
Read more: IFISA uptake surpasses expectations