In most circumstances you should not be required to manually pay for your subscription. This is because when you activate your first paid subscription you authorize us to debit your credit card. This will only occur in the circumstances that your subscription reaches its 'end date' and is about to expire, or when your text credits are about to run out. We do this to ensure your campaign never misses sending a vital text communication.
However, some circumstances will exist where you wish to manually update your subscription. (eg. Credit Card failure)
The following steps can assist you to easily pay for a subscription:
Sign in to your Text Integration account: https://secure.textintegration.com/
Select My Account and then Invoices.
Click View Invoice.
A 'Pay Now' link will appear if you have an amount in the 'Due Now' column. By clicking the link you will be able to pay off the amount that is currently due on the associated invoice.
You may also refer to this video tutorial, How to pay your subscription's failed renewal (VIDEO)