With Scottish Friendly's My MoneyBuilder Select (ISA), you're guaranteed to get back at least what you put in on your 10-year anniversary, provided you make no withdrawals or switch out of the fund. Your money also gains access to the growth potential of the stock market in a tax efficient way.
Remember, the value of investments can go down as well as up, and you could get back less than you've paid in, except on your 10 year anniversary. Tax rules and charges apply including a £50 exit fee in the first 5 years. Cashback terms apply.