How can i avoid accidentally paying invoices twice?

I'll help you avoid accidentally paying invoices twice, @colbert-mrs.

To prevent accidentally paying invoices twice in QuickBooks Online, you can enable a setting that warns you when you enter a bill number that has already been used for that vendor.

Here's how you can set it up:

1. Go to the Gear icon.
2. Choose Account and settings.
3. Click on Advanced.
4. Select Other Preferences.
5. From there, turn on the option "Warn me when I enter a bill number that's already been used for that vendor".

By doing these steps you'll be notified if you attempt to enter a bill with a duplicate number for a specific vendor, helping you avoid paying invoices twice. 

It's crucial to double-check every bill's detail before inputting it into QuickBooks to ensure accuracy and prevent duplicate payments. With this feature enabled, you will have an additional layer of protection against duplicate bill payments.

I have included an article containing guidance on how to manage vendor transactions, track bills, and record payments. You can refer to this article for assistance. 

• How to view and edit vendor transactions in QuickBooks Online
• Enter bills and record bill payments in QuickBooks Online

Please don't hesitate to reach out to us if you have any questions regarding vendor management or other related concerns in QuickBooks Online. We're always here to help you out.

@Aldren18 

RE: To receive notifications of duplicate invoices, simply enable custom transaction numbers that may affect your invoice numbers.

The OP appears to be asking about invoices they pay. Accounts payable invoices. Did you read the question?

@colbert-mrs 

Make sure you enter a bill and then pay the bill instead of using a Check or Expense transaction.  QB can alert you if you're duplicating a bill number: Go to Settings > Advanced > Other preferences > Turn on 'Warn me when I enter a bill number that’s already been used for that vendor'.