You can change your SMS package at any time based on your needs, whether you want to switch to a smaller or a larger plan. If your SMS credits run out, your subscription will renew according to the terms of the new package.
If you switch plans, the new SMS package must be paid immediately.
Step-by-step guide:
Go to your Admin page.
Click on “Account settings” in the bottom left corner.
Click on Subscription
Next to your SMS package, click on Change Plan.
Confirm the purchase.
If you have remained SMS credits, they will be added to the newly purchased credits.