A flexible ISA allows you to withdraw funds from your account when you need it. The money won’t lose its tax-free status as long as you repay the funds before the end of the tax year.

If you were to withdraw funds from a non-flexible ISA account to your bank account, those funds would automatically lose their tax-free status. If you were to pay the funds back into your account this money would count towards your current year’s ISA subscription allowance. So, if you had already fully subscribed and had invested £20,000, then you would not be able to re-invest the money into your ISA.

You can make withdrawals for current year ISA subscriptions and previous year subscriptions. As long as the funds are replaced before the end of the tax year, they will be re-invested in your IFISA and will continue to be tax-free.