If you want to add any value other than the full ReUp value of your current plan, you will need to go to My Account.

Effective February 2012, SIMPLE Mobile will no longer sell nor deliver ePIN's on simplemobile.com. A new, simpler, process now allows existing customers to ReUp their accounts directly without the added step of applying a PIN. Simply visit the SIMPLE Mobile ReUp payment tool. After you verify your phone number, you can ReUp your current plan using a credit or debit card. If you want to change your plan, you will need to visit My Account. After updating your plan in My Account, you can either make a payment within your account or revisit URL. New customers who purchase a SIM + Plan will have a PIN delivered along with their SIM card to their shipping address. At this time, if you wish to purchase Pay-As-You-Go International Long Distance Credit, you will need to do so in My Account.