A third of investors (31%) are increasing their ISA contributions to avoid paying additional tax under the Capital Gains Tax changes announced in the most recent Budget, according to new research.

A further 29% are increasing their ISA contributions ahead of proposed inheritance tax changes to pensions, according to the research from digital wealth manager Nutmeg.

Over a third 37% of investors surveyed in January had not started using their ISA for this financial year.

Just one in five (20%) had already invested the full £20,000 ISA allowance, with women (24%) more likely than men (18%) to have used their full allowance.

A quarter (25%) of investors said that they do not plan to put money into a stocks and shares ISA this year and will keep their funds in cash savings. This rises to 35% among those above the age of 55.

Nearly half (49%) of those prioritising cash savings said they were not feeling confident about securing positive investment returns this year.

Over a third of investors surveyed (35%) said they planned to transfer from old ISAs into new ones before the end of the tax year.

Claire Exley, head of financial advice and guidance at Nutmeg, said changes to personal taxation were the clear driver of investors this ISA season.

She said: “We have seen a clear shift in investor behaviour since the autumn with more people moving their savings and assets into ISAs to minimise the amount of tax they may need to pay. No one wants to pay more tax than they need to.”

• Opinium surveyed 1,000 UK investors on behalf of JP Morgan-owned Nutmeg between 9 and 16 January.