Your dues for a month begin after you complete your first GoPayLater transaction in that month. Your GoPayLater dues will be updated on GoPayLater home, and your limit will change accordingly to reflect your transaction. You can always tap the card (see the image below) to see more information and to repay.

A note on GoPayLater fees: Your outstanding dues will include the GoPayLater fee if the transactions are made after your free trial. Please remember that you only need to pay the fee once per month, and it won't be charged if you don't use PayLater in that month. Besides GoPayLater fee, your dues may also include late fees if you’re past the grace period (5 days after the due date).