is there a way to establish credit limits and block the order desk to enter an order for those clients who have exceeded their credit limit ?

Welcome to the Community, @casi3.

Let me share some insight regarding establishing a credit limit on your credit card to block an order from a client if it exceeds their limit.

Currently, this functionality isn't available in QuickBooks Online. As a workaround, you can manually enter the credit card limit for your customer in the Notes field. I'll guide you on how. 

1. Go to Sales and select Customers. 
2. Locate and choose a customer from your list. 
3. Click Edit. 
4. Select the Notes icon on the top right corner of the Customer window.
5. Enter the information in the Notes field. 
6. Hit Save. 

Following the steps above will guarantee you can indicate a credit limit by adding it to the notes of your customer. 

In addition, I highly recommend using and downloading third-party applications designed to meet your unique business requirements. With such applications, you can simplify your workflow, enhance your productivity, and ultimately you can limit your customer's credit card and block their order if it exceeds their limit. 

If you want to learn how to record payments into your credit card in QBO, you can refer to this article for more information: Record your payments to credit cards in QuickBooks Online.

Feel free to leave a comment below by hitting the reply button if you have other questions regarding the credit card limit in QBO. The Community space is always here to help you.

3-7-24

Since no one has updated the directions on how to enter the credit limit on the customer card.

Edit "Customer"

Go to the "Payment Section"

Enter the amount in the "Credit Limit" field

-NOTE: as of right now I do not see that the system is alerting me that the test customer has a credit limit when testing a fake invoice.