During the setup process Gradwell will have applied a credit limit to your reseller account. As customers sign up to services through you, the wholesale value of their purchase is deducted from this credit limit.
Once a wholesale invoice from Gradwell is paid by you, your credit limit is updated to reflect this. If you reach your credit limit then customer orders will not provision.
This article explains how to check your credit limit remaining.
If you wish, you can configure Auto TopUp, which will automatically make a payment on your account when your remaining credit limit reaches a defined level.
To configure Auto TopUp, login to your control panel and select Billing from the top right corner.
From the left menu, select My Reseller Status.
Your credit balance (less any not invoiced purchases) will be shown. Click Change TopUp Options.
You can configure the remaining balance threshold at which an automatic top up will be made, and also the amount you wish to pay.