Putting sim into different phone

[annie24]

My son has given me his old iPhone and put some credit on it with giffgaff. When the credit runs out can I just put my sim card from my phone into the iPhone and keep the same payg tariff and number? Sorry, I have no confidence to try it!

[madasaf1sh · Accepted solution]

@annie24 

Yep you just your sim straight into the phone., and everything stays the same. 

[annie24]

Great,thanks