My husband and I recently noticed a debit charge from his bank statement online once it was through pending the charge was a Legal Order Fee (lts). He had gone to the bank to get this situation understood and under control. It turns out it is child support and the bank is charging him the $100.00 to get into his account while the next direct deposit from his employer will be seized for $800.00. So he basically canceled all of his direct deposit as well as any and all automatic bill pay.
To the point our question is how did child support find this account, he pays monthly out of his check for child support and this is back pay. He thinks that the ex somehow got a control of his account number but what other ways does Child Support have of gaining access to his personal checking?

The only way they can do it is by court order. And he shouldn't have a charge for it other then the actual amount. Are you sure its child support related? Did the bank show him an order?

Child support enforcement ( if he has past due support) may have found it, his ex may have told court where the money was to be found.

The bank would have had to been given a court order to take money out of the account

As the others have said if it is child support then the bank would have a copy of the order from the court because they have to have one to take out the money. There are a few ways that they can get the account. The ex could have told the child support enforcement where he banks at or he could be behind enough to issue an order to attach his bank accounts then child support enforcement can find it. That is their job to enforce the payment of child support. That includes arrears that have added up.