How long does a data pack last?

This is the detail people most often miss. Most booster and add-on packs are tied to your base plan and expire the moment your plan's validity ends — so if your cycle resets in two days and you buy a big pack today, you'll lose whatever you haven't used. Some packs have their own short window (a day, or 30 days), and standalone data-only packs usually carry their own separate validity. The rule of thumb is to match the pack's life to when you'll actually use the data: near the end of your cycle, buy small; if you need data over a longer stretch, choose a pack with its own extended validity. We always flag the validity so you don't pay for data that expires unused.