The amaysim catalogue lists its plans by cycle length, and the important word on that page is lock-in: the provider states no lock-in contract on the plans it lists.
What the catalogue states about the cycle
| Plan | Price | Cycle | Data |
|---|---|---|---|
| 10GB | $14 | 7 days | 10GB |
| 30GB Data Plan | $25 | 28 days | 30GB |
| 120GB | $50 | 28 days | 120GB |
| 240GB | $320 | 365 days | 240GB |
Each of those is a separate purchase with its own cycle. A 28 day plan is a 28 day cycle; a 7 day plan is a 7 day cycle.
What triggers the next recharge
Nothing automatic. On a no lock-in prepaid product the next cycle starts when you buy the next one. That is the trade for the flexibility: no commitment, but also nothing running in the background if you forget.
What we could not verify. Where a provider has not published a figure we mark it unknown rather than estimate it. Re-read the provider page linked below on the day you decide.