Postpaid is a billing system commonly used by mobile phone service providers, where customers receive a monthly bill for their usage. This plan allows users to enjoy services like calls, texts, and data without needing to pay upfront. Instead, they are billed at the end of each billing cycle based on their actual usage. In a postpaid plan, customers typically sign a contract for a specific duration, often 12 or 24 months, with a set monthly fee. This fee may include a certain amount of data, calls, and texts, and any additional usage is charged separately. Postpaid plans often come with perks like discounted devices or loyalty rewards.