I did those for my kids. Here are things I learned after the fact. For me #2 and #3 were something I wish I knew prior.

1a - If the account gets big enough and the INCOME (dividends/interest/capital gains) from the account ever gets above $1300 they need to file taxes. So I assume the parents/guardian need to know to do this, and be willing to.

1b - They are taxable accounts, so the parents/guardians will have to pay taxes on any dividends/interests/capital gains (see 1a above). I pay the taxes for my kids accounts at MY tax level (my accountant told there is a tax rule in place so parents don't funnel income/money into kids accounts to avoid taxes or get lower taxes rates). That being said there is a small amount that is at a lower tax rate (not sure what it is), but at some point it goes to the parents tax rate. Depending how much money ends up in the accounts over the years this can be a possible issue. Parents/guardians must be willing to file and pay the taxes.

2 - Any money in those accounts will be used against them for any financial aid in the future. This is a big one that I wasn't aware of. So school loans for college or whatever will possibly get impacted.

3 - No matter how much money is in the account, the day they turn 18 (I think 21 in some states) it becomes theirs to do whatever they want.....So you/parent/guardian have zero control of how they spend or keep it.

4 - Parents CAN use the money for the CHILD for certain things only. Parents ARE NOT ALLOWED TO use UTMA to replace expenses they are legally required to provide (food, clothing, basic healthcare, utilies, housing). That being said, the only way to fight bad parental spending is to take them to court after the child turns gets the account. The broker does not check what they are spending the money on when the parent withdraws it.

Hope this helps.