Websimply use your 8 digit account pin or answer your security question. (both are used when calling customer service or making changes in store). Webnow when i try the guest pay option using my account number, i get “we are unable to accept guest payments from this phone number provided at this time. When i make my payment if i can not make it. On the limit date. Webthe website also gives the option to pay bill as a guest but still requires a tmobile phone number or account number to pay a bill as a guest. My question is if i bought the service.