How do I add late fees to overdue invoices?

I'd be glad to walk you through how we can manually add late fees to overdue invoices in QuickBooks Online (QBO), @accounts-horti-t.

When applying late charges to your invoices, first, we'll have to turn on the late fee setting. To do that:

1. Go to Settings, click Accounts and Settings.
2. Select Sales, and tap Edit under the Late fee section.
3. Turn on the Default charge applied to overdue invoices, and enter the necessary details.
4. Select Save.

Once done, let's create a product or service item for them. Then, manually add them to your invoices as a line item if you haven't sent them yet, or create one for the fee to send to your customer. 

Here's how:

1. On the Gear icon, select the Products and services tab under Lists.
2. Click New and choose Service.
3. Enter the late fee name.
4. On the Category dropdown, select the category that best describes the fee. Learn more about item categories.
5. Input all the necessary fields needed, then click Save and close.

Once done, let's apply the late charges to an overdue invoice. Here's how: 

1. From the left menu bar, click Sales.
2. Tap the Invoices tab, and choose the specific invoice you want to add to the late fees.
3. In the Product/Service dropdown, select the late fee item you created.
4. In the Message on invoice section, include a note about the invoice the fee is related to.
5. Select Save and send or Save and close. 

Also, you can customise your sales forms to inform customers about the late fees for overdue invoices. This way, you can include a default email message you send along with the invoices.

Moreover, to gently remind customers about invoice due dates, you can check out this article to set up automatic reminders: Send invoice reminders automatically or manually in QuickBooks Online.

I'd be glad to hear more from you, accounts-horti-t. If you have any additional questions about applying late charges on overdue invoices, feel free to comment below. Stay safe!