I can't get my custom invoice numbers to print on my invoices; the field is coming up blank.

Hi there, @admingrandenviroca1.

Thanks for coming to the Community. I'd be happy to help share some steps on how you can get the invoice number to when printing an invoice.  

If the invoice number is not showing up upon printing an invoice, you need to check if the Form Numbers option enabled on the invoice form style that you use. Let me walk you through so you'll see the number on your actual invoices.

Here's how:

1. Click the Gear icon located in the upper right-hand corner.
2. Under Your Company, click Custom Form Styles.
3. Click the Edit link of the default invoice template.
4. Click the Content tab, and click the header part of the invoice to expand more options.
5. Under Form, check the Form Numbers box.
6. Click Done.

To learn more about customizing sales forms in QuickBooks Online, you may visit these articles:

• How to change the invoice number on sales forms
• How to customize invoices, estimates, and sales receipts

That should do it!

Please let me know if I can be of additional assistance with printing invoice numbers in QuickBooks. I'll be around to help you out. Have a fantastic weekend!