Can someone tell me why qbo is bringing up an old used invoice number when I go to add a new invoice?

QuickBooks only relies on the last invoice number you created. You may use an invoice number that has already been used. With this, QuickBooks Online (QBO) brings up the old used invoice number when adding a new invoice. Poe. Let us tackle this more.

When creating a new invoice, you may use the same invoice number that has already existed. It causes a sequence of continuously used numbers for each new invoice. I recommend manually adjusting the sequence based on the last number used for the previous invoice. For instance, if the last invoice number was 50, then set the new invoice number as 51. It will ensure that the numbering continues correctly for subsequent invoices.

To verify the exact order of your invoice sequence, you can check the last number used in the All Sales section. It will allow you to continue the numbering for your following invoices. Here's how:
 

1. In Sales, click Invoices.
2. Scroll down to check the last number used for the invoice.
3. Once confirmed, update the new invoice with the succeeding sequential number.

The provided picture is sample only to help you verify on where you can see the invoice number. 

On the other hand, know that you can also personalize your invoices or any QBO sales forms to fit with your business-looking standards.

Mention me for more questions about handling your invoices while utilizing QBO, Poe. I'm here to guide you in many ways.