You can provide a direct link to your customer to a specific page within the Customer Portal.
Once in the ReCharge Dashboard, click on the Customers tab at the top.
Search and select the desired customer.
Select the page you want to link in the menu on the left. Hover over the link pictured below to copy the URL and paste to your customer.
If you wanted your customer to update their credit card information, you would select Billing Information pictured above and then copy the link from that page to share.