Manage customers and income

I can share some insights about character limitations, @AmyPhil.

Are you referring to the Message displayed on invoice and Message displayed on statement field in your invoice? If so, the character limit for The invoice field is 1000 and the statement field is 4000.                                            

The feature to expand the maximum number of characters you can enter in each field is currently unavailable. That would be a great addition to the current features that we have for invoices. I'll take note of it. 

You can check this article for more information: QuickBooks Online file size and feature limits. You can also visit the QuickBooks Blog to check for new updates and features that we have. 

You can also attach a document to your transactions. Check this article for your reference: Attachments in QuickBooks Online.

If you have follow-up questions about character limits or if you mean something else, let me know in the reply section below. I'm always ready to assist. Have a great rest of the day!