No. Unused data does not roll into the next day or the next plan, and it is not refunded.
On an unlimited plan this barely matters: there is no pot to waste, only a daily full-speed amount that resets.
On a fixed-data package it matters more. Buy the size you will use rather than the size that feels safe.
The eSIM stops carrying data. Nothing is charged after that, and nothing renews by itself.
Some eSIMs can have more added to them — more days on an unlimited plan, more data on a fixed-data one. Your order page shows what your own network will accept.
Where nothing can be added, buying again is the way to carry on. That is a new eSIM to install.
Choose unlimited if you do not want to watch a counter. There is no total allowance to run out, so a phone update or a photo backup cannot leave you offline outside the airport.
Choose fixed data if you know roughly how much you need and want the smallest possible price. A light week of maps and messages can cost less on a small fixed package.
The difference that matters on an unlimited plan is the daily full-speed amount, not the total: every unlimited plan states how much runs at full speed each day and what speed it continues at afterwards.
Validity is counted in days from the moment the plan started, and it ends at the same time of day on the last day. A seven-day plan that started at 14:00 on Monday ends at 14:00 the following Monday.
It is not a calendar count. Landing in the evening does not cost you that day.
After that the eSIM stops carrying data and nothing further is charged.
Ask us — a person answers, usually within one working day.