Asda sim mobile phone

Good afternoon

Hope everyone is as well as can be expected.

I have a problem with my English mobile sim card.

I am with Asda at the moment. I have had them for many years and always found them good. Unfortunately, they are changing their service provider to Vodaphone from the EE we have now.

Not a problem with that except that I cannot change my sim in Spain. The phone has to be in the uk when the swop over takes place. The number is on everything that needs a uk number so would be a pain to change.  

Does anyone else have this problem and anyone managed to get around it. 

I have the Vodaphone sim here but not sure what to do with it. 😉

Any help would be greatly appreciated.

Thank you