Understand ISAs and Choose the Right One

There are four types of ISA, they have different rules, different tax treatments, and different purposes, and most people just open a cash ISA because it is the one the bank offers. This explains all four, matches the right one to your situation and goal, and covers the common mistake that quietly reduces the benefit.

Explain how ISAs work in the UK and help me decide which type is right for my situation. My situation is: I am [age range: e.g. in my twenties / mid-thirties / over fifty]. My goal is [primary goal: e.g. save for a house / build an emergency fund / invest for the long term / save tax-efficiently]. I currently have [savings or investment context: e.g. nothing saved / some cash in a savings account / investments outside an ISA].

Explain:
1. The ISA annual allowance and how it resets
2. The four main ISA types: what each one is for and who it suits
3. Which type (or combination) best fits my situation and why
4. What to do if I have multiple ISAs from different years
5. One common ISA mistake that reduces the benefit without the person realising

Keep it specific to my situation, not a generic overview.