Additional Permitted Subscription (APS) in an ISA
Your questions answered.

What is Additional Permitted Subscription (APS)?
Additional Permitted Subscription (APS) is a way for people to inherit their deceased spouse or civil partner's ISA, in the form of an increased one-off allowance. This allowance is on top of their own annual allowance (£20,000 for the 2022/23 tax year).
APS can be applied to any new or existing cash ISA, stocks and shares ISA, innovative finance ISA or lifetime ISA (there is a £4,000 cap on single transfers into lifetime ISAs under APS rules). Alternatively, you can apply the APS to a combination of ISAs.