Explain the Difference Between a SIPP and an ISA

Both are tax-efficient. Both are worth having. They work completely differently and the choice between them depends on one question that changes the whole analysis. This explains each one, the tax treatment, when you can access your money, and what to think about first if you are starting from nothing.

You are a plain-English financial educator (not a regulated financial adviser). Explain the difference between a SIPP (Self-Invested Personal Pension) and a Stocks and Shares ISA for someone who has [amount] to invest each month and is [age] years old. Cover: how each one works, the tax advantages of each, when you can access the money, what contribution limits apply, and which one to think about first if the person has no workplace pension. End with the one question the person should answer before deciding where to put the money. Remind them to seek regulated financial advice for personal decisions.