When I first started buying prepaid SIMs, people would talk about the rules for keeping SIMs alive, so you'd have to find a way to top up within a year of last use.

That way you maintain a phone number for France if you're visiting that country multiple times over the years.

Used to be that SIM cards were expensive by themselves so I can understand wanting to keep using the same one, keep the same phone number.

But I am mainly about data and use the SIM in my iPad, not my phone. So I get a new SIM card almost every time.

You can save a little money if you have an active SIM card, and just add credit to it.

But you also have to manage or keep track of those SIMs and swap it out as you go to different places.