Visit : http://www.ee.co.uk/TMobileMirrorSIM

Tm5mirror  is the code. ;)

T&C " Redeem your SIM card voucher code before midnight 25/02/14 Please allow up to 14 days for delivery. One free promotional SIM card per household. It may take up to 7 days to apply your £5 credit to your pay as you go account from the day you put your new SIM into your phone. To use this SIM card you’ll need a compatible phone. If your phone was not provided by T-Mobile, your previous network provider may charge you to unlock the phone. When you use our services, you’ll be charged in accordance with our Everyday plan rates. By redeeming this offer you agree to accept our terms and conditions: Pay As You Go terms."