£80 billion was subscribed to ISA accounts during the 2015/16 tax year, according to figures released by HMRC.
This is an increase of £1 billion compared to 2014/15. Individuals saved an average of £6,338, a record high of 5% on the previous year.
These results follow changes to ISA regulations implemented on 1 July 2014 which saw the annual limit move from £12,000 to £15,000.
Overall market value of ISAs stood at £518 million while value in cash ISAs and stock and shares ISAs increased by 6% and 9% respectively.
- £921 million was subscribed to junior accounts in 2015/16, with 60% of the amount in cash
- Savers aged 65 and over had the highest average savings value of £37,864 compared to active savers under 25
- End of 2013/14 tax year saw 44% of people open an ISA, with those of high value than in Wales (42%), Scotland (30%) and Northern Island (30%).
Further ISA changes are due to take place from April 2017. People aged under 40 will be able to open up a Lifetime ISA and save up to £4,000 per year.
The annual limit a person can save each year will also rise from the current £15,240 to £20,000.