Although it might seem easier at the time, when it comes to informal payments for child support the best policy for both parties is to avoid them.
For obligees (people receiving child support), it is usually best to require your ex to make payments through the State Disbursement Unit. The Office of the Attorney General in Texas keeps records of payments received. These records help in enforcing child support against a non-paying ex. Requiring payment through the State can also be a good thing in cases where it is necessary to limit contact between the parties.
For obligors (people paying child support) it is important that you strictly follow your child support orders as to the date, amount and method of payment. If your decree says to pay your child support through the State Disbursement Unit, then do it. Informal payments to your ex will not appear on the payment records kept by the Office of the Attorney General. This causes problems when a less-than-honest ex tries to double-dip and denies receiving payment. If you do decide to make an informal payment, always retain proof (like copies of a check or affidavits of informal payment) in case this issue arises.
For obligees and obligors alike, you must understand your child support order and what it means for you on a day-to-day basis. If something is unclear or if you are having problems with receiving payments or getting credit for payments, contact a family law attorney for a consultation. Do not delay - failure to pay court-ordered child support can be serious, resulting in fines and even jail in some cases.