Template changes don't stay change

Thanks for posting here on the Community, @avcraftinc.

Allow me to help you save the adjustments you've made to the invoice.

In QuickBooks Online (QBO), we can modify the invoice number on a single transaction to any number we prefer. The invoice number displayed afterward will automatically adjust in sequence. So, for instance, if we set the current invoice number to 1234, the system will automatically generate invoice number 1235 when you create the following invoice.

I'd love to share a screenshot where we're able to change an invoice number:

After changing the number, make sure to click anywhere on your screen to let the system load the changes. However, if you mean changing the invoice number to a particular same number, you'll have to manually change it every time you create one.

On the other hand, if you're referring to modifying the invoice template, then we need to be sure to set your customized form as the default one so that we can use it each time we make an invoice. Here's how:

1. Go to the Gear icon and select Custom form styles.
2. Make the necessary changes you want then click on Done.
3. In the Custom form styles page, locate the customized form you've just made.
4. Click on the drop-down button beside Edit.
5. Select Make default.

Moving forward, you'll be able to utilize the form.

I've added an article here that you may read through in case you want to create custom fields not just on invoices but on all sales forms: Add custom fields to sales forms and purchase orders in QuickBooks Online.

Should you need any additional assistance in managing your invoices, don't hesitate to leave a reply. I'm always around to help. Have a great day!