Rollover rule
Unused subscription tokens do not carry over to the next billing cycle and expire at the end of each subscription period. This keeps the monthly plan tied to current usage instead of building an unlimited balance over time.
What to do if you need more
If you use more than your subscription includes, purchase a one-time token pack. One-time packs are useful when you need extra capacity for a launch, seasonal campaign, large batch of visual concepts, or additional marketing assets.
To avoid waste, plan large generation work near the beginning or middle of your billing cycle, and use the token balance shown in the app before starting large actions.