To pay early or make a manual payment using the Zip Customer Portal, go to https://customer.us.zip.co/en-US/login and log in via verification code, using either your mobile number or account email.
Once logged in, at the top of the page, select Orders.
Click View Order next to the order you’d like to make a manual/early payment for.
Select Pay Now next to the upcoming installment you’d like to pay.
At the top of this page, select the card you’d like to use, then click Make Payment.
Shown in the previous screen shot, you may also Add a New Card from this page as well. However, you will still have to repeat steps 1-4 to then use it for your manual payment.