This key's credits and the billing rule

Balance, tier and what is billable, for the key on the request. Read it before starting a batch rather than discovering the wall mid-job. One credit answers one distinct serial, any Apple device and any year, and the same serial again within 24 hours is free. Answers that come back retry or unsupported, and every endpoint other than lookup, are never charged. Credits are prepaid and do not expire. Rate limits: 20/min and 500/day per anonymous IP; 200/min and 5000/day with a free key.