Billing issue. updated Credit card but cant proceed to make payment

Welcome to the QuickBooks Community, @oneexcelglobal.

Let’s take a few troubleshooting steps to help fix this so you can make payment using your updated credit card. To start, access your QBO account using an incognito browser. Private mode prevents storing cache and web history to avoid issues when running frequently visited websites. Below are the shortcut keys they can use: 

• Google Chrome: press Ctrl + Shift + N 
• Mozilla Firefox: press Ctrl + Shift + P
• Microsoft Edge: press Ctrl + Shift + P
• Safari: press Command + Shift + N

Once signed in, make a payment again. If you don't experience the same thing, you have to clear your browser's cache to have a clean slate. If the same result, use another supported browser. 

However, if the issue persists, I suggest reaching out to our Customer Care team to check your account's status. They can pull up your account in a secure place and determine what's preventing you to process payments after updating your credit card. Here's how:

1. Go to the Help menu.
2. From the Assistant tab, type your concern. Example: Can't make payment using an updated credit card. 
3. Then, type Talk to a Human and click the Get help from a human option.
4. Choose either Chat or Callback. 

Our support operation hours are from Monday to Friday 9:30 AM to 6: PM. To know more, see this link: QuickBooks Online Support.

Community articles are also a great help to guide you with your QuickBooks tasks. You can either save them or bookmark them for future use. To do so, just type the keyword of your concern in the search bar or select any of the categories displayed. 

Keep me posted if you need further assistance processing payments in QuickBooks. I'll be on the lookout for your response. Take care always.