Hello @Mohammed Faisal ,
If your default payment method is credit card, then the system will automatically charge the credit card on file on the 11th day from the invoice generation date.
If your default payment is check/wire-transfer, then you will have to pay the due invoice within the 30 days from the invoice generation date.
If you have past due invoices and you need urgent help to make sure your subscription is not disabled, l request you to contact our Azure Billing and Subscription Management Support team for more information, Billing/Subscription support is free for all Azure customers, you can create a free ticket here: https://portal.azure.com/#blade/Microsoft_Azure_Support/HelpAndSupportBlade/newsupportrequest.