Buying an O2 payg phone for my GiffGaff SIM

[Anonymous]

When you buy an O2 payg phone you have to specify a tariff on top of the "up front cost" . What am I commiting to here?. Will O2 charge me anything above the up front cost? As stated above, I want to use my existing GiffGaff SIM.

Thank you in advance for any clarification you can provide.

Steve

[MI5 · Accepted solution]

You'll only pay for the first top up.
If you don't want the o2 sim, just don't top it up.

[jonsie]

Pay for the first top up, use the allowance and then put your giffgaff sim in the phone. 

[Anonymous]

Thank you MI5 and jonsie  for your clear replies. I think you knowlege here is the only source on the internet to address this topic. 

Steve

[MI5]

Just one thing to check on your account that auto top up ISN'T enabled - it shouldn't be, but just check to be sure.

[Curr946]

Could just sell the sim to get most of the top up value back.