> Can a kid set up an AWS account?
Yes
> Are there no checks?
No
>Wouldn't the contract be void for anyone underage anyway?
Typically not
Presumably companies can't enforce debts against children [who are under the age of criminal liability, which is under-10 in UK].
I knew that in Germany contracts with minors are voidable. After some checking they apparently are voidable in the U.S. as well:
> Contracts with minors are voidable at the minor's discretion but exceptions exist, such as contracts for necessities (e.g., food, health, and transportation).
[1] https://www.upcounsel.com/minors-and-contracts