Why does it keep saying invoice number already used when it is a new number

Bingo!!!!

Thank you for bringing this issue to our attention. I understand the frustration of encountering discrepancies with invoice numbers. I'm here to assist you with the discrepancies  invoice numbers@jason192 .

Have you already tried the troubleshooting steps recommended by my colleague? This issue may be related to your web browser. It is recommended to clear your browser's cache and cookies or try accessing QuickBooks Online from a different browser or device.

By default, QuickBooks Online generates invoice sequence numbers starting from 1001. Additionally, QuickBooks Online automatically detects if there is already an existing invoice with the same number. I suggest checking the audit log in QuickBooks Online to see if the invoice was created but is not visible in the list of invoices. The audit log provides valuable insights into changes or actions that have occurred within your QuickBooks Online account. 

Here's how:

1. Go to the Gear icon.
2. Choose Audit Log.
3. From the Filter drop-down, choose the appropriate User, Date, and Events filter.
4. Click Apply.

I'll include this article again if you need more details about the Audit Log: Use the audit log in QuickBooks Online.

To learn more about invoice numbers and how to assign them, please refer to this article: How to assign invoice numbers: Definition & examples.

You can also save time by creating recurring invoice transactions to schedule an invoice.

If you have any further questions about QuickBooks Online or invoice numbers, please feel free to comment below. I am always here to assist you.

I'm here to help you locate duplicate invoice numbers to prevent discrepancies and errors in financial records, @Elissiah. 

To locate the invoice that contains duplicate transaction numbers: 

1. Hover to Sales, then select All sales. 
2. Select the NO. column to sort your transactions
3. Check for duplicates.

You can run a customer report to view all your sales transactions clearly.

1. Go to Reports, then enter Transaction List by Customer in the search field.
2. From the Report period dropdown menu, select All Dates.
3. Select Sort dropdown.
4. From the Sort by dropdown menu, choose Num. Then select Ascending order or Descending order.

You'll see a list of your invoices, sales receipts, and other sales transactions listed in numerical order.

Moreover, you can set up automated reminders for your customers when your invoices are due. This feature can help you get paid faster and reduce the number of overdue payments. 

Just tap the reply button and enter your response whenever you need further information regarding your duplicate invoice numbers. I'm always here to help you. 

I completely understand how challenging it can be to see that error, @cr8vrlj, especially when you know you haven't used that number on a visible invoice. I've gathered some information about Sales Order conversions and numbering that should help us fix the problem and get you back to invoicing smoothly.

QuickBooks Online (QBO) aims to protect your financial data by ensuring every transaction has a unique ID. When you convert an estimate to an invoice, the system immediately reserves the next available number in the sequence for an accurate audit trail. Sometimes, due to a momentary data interruption. The system successfully reserved the next number in the sequence for the conversion, but the invoice wasn't fully saved within QBO, prompting you to use the next or a different invoice number.

We can rectify this by using the Custom transaction numbers feature. It will help us temporarily skip that reserved number and direct the system to the next clean starting point.

Here's how:

1. Go to the Gear icon and select Account and settings.
2. Navigate to Sales, then the Sales form content section.
3. Turn Custom transaction numbers on.
4. Click Save, then tap Done.

Next, create a new invoice and manually enter a number that is safely past the last number you see (Example: if the last one was 1012, we'll enter 1022). It will tell QuickBooks that the new sequence starts after this number. Once done, save the temporary invoice and try converting your Sales Order again.

Once everything is working correctly, you can safely remove the temporary invoice by deleting or voiding it. After that, return to the Account and Settings menu and turn off the Custom transaction numbers feature to restore the default numbering system.

Let me know by leaving a comment below if you encounter any difficulties while following these steps or if the problem persists. We're here to support you and ensure your QuickBooks experience is as smooth as possible.