I'm going to switch carriers soon and port my two numbers but I don't know exactly when to do this during the billing cycle. I'm not under a contract with either phone - both are paid in full. My bill is due on the 26th. My billing cycle ends on April 3rd. Is the bill that is due now for service that already occurred or will occur in next month? I've read that I should port about 5 days before the billing cycle ends but if I'm getting billed in advance, why would I pay the bill that is due now? So confused.