Really stupid question about a mobile phone

[LaBelleDameSansPatience]

Dh has a simple phone he hardly ever uses. It has finally run out of its initial £10 credit. He needs it on Sunday. How can he top it up? He doesn't know what network it is ... Bought maybe 2 years ago. (He really hardly ever uses it!)

[Justmuddlingalong]

Will the network provider be on the sim card?

[LIZS]

If he hasn't used or topped it up in last few months it may well have expired. If he buys a new payg sim card (from supermarket or newsagent) he can top it up at a cashpoint.

[LaBelleDameSansPatience]

Will that mean a new number?

[LIZS]

Yes, it may well have been reallocated by now anyway.

[flickyhair21]

When the phone is turned on is there not something saying what network it is on based by the signal strength?