Which day does this plan expire

It depends on that plan's policy. On a plan that counts from first connection, buying ahead costs nothing as long as the line stays off. On one that counts from the order or from a chosen date, buying too early genuinely wastes days — so read the activation line first.

If the phone registered and the plan counts from first connection, the clock has usually started and cannot be reversed. Switch the line off so it stops spending data, then contact us with your order number. We will check what that plan's terms allow, and say so plainly if the answer is nothing.

It varies. Some plans add data and keep the original expiry, some extend the days, and some cannot be topped up at all. It is stated on that plan's detail page. If it reads unclearly, ask before you rely on topping up as your fallback.

Data and validity are two separate conditions, and the plan works only while both hold: data remaining and the date not yet reached. If the data goes first, what follows depends on that plan's terms — topping up, buying another plan, or whatever its page sets out.

For a plan counting from first connection, enter the day you will switch the line on and let it register at the destination, which is usually your arrival day. Installing the profile at home does not start the clock, so it is not the date to use here.