We are offering several Payment Gateways and some of them involves a delay into processing the Payment and transmitting the confirmation to our billing system that the payment has been processed. It leads to the invoice to remain unpaid while the payment has been made. 

2checkout

2checkout performs some background check on the payment with a delay that differs between a few minutes to up to 12 hours. If the delay exceeds the 12 hours, or if the Payment has been declined, we will be notified and we will be contacting you. 2checkout would also informs you of the status. 

Coingate / Coinbase - CryptoCurrencies.

All CryptoCurrencies relying on the POW (Proof Of Work) are requiring some network verification of the transaction and the Payment Gateways such as Coingate and Coinbase expects up to 6 verification for the transaction to be validated, such verification according to the Currency network load may take up to 12 hours. In which case, you would just need to wait.

You may review the Payment status from the transaction link you were provided during Payment. 

If the delay exceeds 12 hours for the mentioned Gateways, or if the Payment Gateway isn't listed in here, you may open a support ticket at the Billing Center with as much details you have on the transaction for us to review it for you.