Why did my invoices generate with the same invoice number?

Thanks for posting in the Community, sharlien!

Let's check if you have set up a recurring invoice template in your QuickBooks Online file. For invoices created manually, the system will prompt you if a duplicate invoice number has been entered. 

To check the duplicate invoice number was entered manually or through recurring invoice.

1. Click and open the invoice.
2. Click on More.
3. Click on Audit history.
4. Check if the invoice was created by a specific user or by System administration. System administration means you have set up a recurring template.

Furthermore, you can enable to Custom transaction numbers option for you to enter your own invoice number sequence. Once you have set up your custom invoice numbering, turn off the Custom transaction numbers feature. This will help prevent accidental changes to your numbering. 

1. Go to Settings ⚙ and select Account and settings.
2. Select Sales, then select anywhere within the Sales form content section.
3. Turn Custom transaction numbers on or off.
4. Select Save, then select Done.

You can check this link to learn more about Add custom transaction numbers to sales forms in QuickBooks Online.

Feel free to post your concerns in the Community or click the Reply button for follow-up questions. We'll be happy to help. Have a good day!

Hi there

Thanks - this was definitely manually entered, this happened to a client of ours and I have since gotten more detail -now - her last invoice number was 1381 - she then (straight after the creation of invoice 1381) manually started a new invoice and the number went to 1380 - once she sent the invoice the customer pointed out the number was duplicated.  She then started another new invoice and the number went to 1381.  So she started another new invoice, this time the number was 1382, so she continued with that one, sent it, and deleted the other two that had the duplicated 1380 & 1381 numbers.  I feel like this might have just been a QBO "hiccup" on that day, what do you think?

Thanks for getting back to us, sharlien.

That is a possibility of what happened that day. With the invoice number, once you have set up your custom invoice numbering, QuickBooks will follow the sequence you set up. When you delete an invoice, and re-entered the invoice number from the deleted invoice, the system will start and follow that sequence on your next invoice.

I recommend running an Invoice List report, that way you can check what invoice number to start on your next invoice. Or if everything is correct, you can follow the steps in this link and turn on and off the custom transaction numbers.

Please let me know if you have any additional questions. I'm always willing to assist.