A top-up adds more data, or sometimes more time, to an eSIM plan that is already sitting on your phone. Instead of installing a fresh profile, you buy an allowance that gets attached to the plan you are already running, so the same eSIM keeps working without any reinstall. People also call it a recharge, a refill, or simply adding data.
The alternative is buying a new plan outright. That means a separate one-off purchase with its own allowance and its own validity period, which you activate when you are ready. Neither route is a subscription: an eSIM is always a prepaid, one-off buy, and nothing renews or bills you again unless you choose to purchase more.
So which makes sense on a trip? If you are mid-holiday, your current plan still has days left, and you have just run low on data, a top-up is the tidy option: the same eSIM keeps its settings and you avoid juggling profiles. If your plan has already expired, or you are moving to a different region with different coverage needs, a new plan is usually cleaner and often better value than stacking top-ups. Heavy streamers should also glance at the fair usage policy, since speeds can be managed once you pass certain thresholds regardless of how you added the data.
Watch the calendar either way: a top-up that only adds data does not always extend the days remaining, so check what you are buying. New to the format? Start with our guide on what is an eSIM.