How do I set up late fees/interest on invoices in QB online?

We're happy to see you here today, @fg08. It's my pleasure to walk you through setting up late fees on invoices in QuickBooks Online (QBO).

First, you'll need to enable the default late fee settings to apply them to your customer's overdue invoices. Here's how:

1. Go to the Gear icon and select Account and Settings.
2. Go to Sales and click Edit in the Late Fees section.
3. Switch on the Default charge applied to overdue invoices.
4. Enter the Amount and/or Percent (%) of the fee.
5. Choose how often you charge your customers in the Frequency dropdown.
6. Edit the default name and click Save.

Once done, QBO automatically creates an income account to track the amount of fees you've collected. For more information, please refer to this article: Apply late fees to overdue invoices automatically in QuickBooks Online.

Furthermore, you can personalize your sales forms in QBO by utilizing the tools available in the program. Doing so allows you to create professional designs for your invoices and include information relevant to your business needs.

Please stay in touch whenever you have follow-up concerns about late fees. We're always available 24/7 to address your questions. Take care, and have a great day ahead!