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 balance pays for everything: a revealed or exported contact costs one credit, and checking an address on your own list costs half a credit. A check balance from before 2026-09-19 is spent first when you verify a list.
Everything is transactional. Each spend is tied to the batch it came from, so your credit history always shows where a credit went. If a request needs more credits than your balance holds, it fails cleanly with a 402 and nothing is deducted at all. Partial charges do not happen.