If you hold credits from more than one source, the order they are consumed in is fixed and automatic. You never choose it, and you cannot lose value by holding several kinds at once.
- Plan and bundle credits first, because they are the ones with an expiry date attached to a billing period. Within that group, the batch that expires soonest goes first.
- Then packs and wallet top-ups, oldest purchase first.
The logic is simply use-it-or-lose-it before keep-it. Your monthly allowance is drained before the prepaid balance you bought separately, so the prepaid balance survives to the next cycle instead of your allowance quietly expiring unused.
One rule sits above the order: credit classes are never mixed. Contact credits pay for reveals and exports of our data. Verification checks pay for verifying lists you upload. A shortage in one pool is never covered from the other, in either direction.
Everything is transactional. Each spend is written against the specific batch it came from, so the ledger always explains where a credit went. If a request needs more credits than the whole class holds, it fails cleanly with a 402 and nothing is deducted at all. Partial charges do not happen.