From what you have written, it seems that your son may have been in an accident where he was injured, there was a settlement and the settlement money is in a blocked account. Assuming this is the case and you need to pull money out of the account to benefit the child, you would need to file a petition with the court in the same case as the presumed law suit seeking the relief you want.If the above example with a prior personal injury is not the case where there was no prior court action with your son, you would still need to file a petition with the court seeking release of a certain sum of money for the child's benefit. In order to do so, I suggest that you consult with an attorney experienced in "blocked accounts" for minors.