Question: what is the best way to invest money for my child?
Answer: Bank/building society accounts. Opening a children's savings account with a bank or building society is a good place to start; and unlike some ISAs, they offer instant access to funds. ... 
Junior ISAs. ... 
National Savings & Investments Children's Bonds. ... 
Trusts. ... 
Junior Self-Invested Personal Pension (SIPP)