Can I set it up that my customers have 7 days to pay the invoice? It doesn't give 7 days as an option.

Good day, @fairless947-btin. I'm happy to assist you with setting up seven days intervals for the pay date of the customer's invoice in QuickBooks Online (QBO).

I understand that having transparent payment terms can help ensure you get paid and makes it easier for your customers to understand your billing process. With that, you can use the Terms section to add the period for your customer to pay the invoice. I'll show you how.

1. Go to Sales, then click Invoices.
2. Choose one from any of the listed invoices.
3. Click Edit Invoice.
4. Under Terms, select +Add new.
5. Enter Net 14 in the Name text area.
6. Type 14 in the Days field below the Due in a fixed number of days option and Save.
7. Then you can click Save and Send or Save and Close to confirm the changes made.

You can also go to the Account and Settings section and set it to 7 days for invoice payment terms in QBO.

Here's how:

1. Click the Gear icon at the upper right corner and choose Account and Settings.
2. Select the Sales tab in the left panel and select Sales format content.
3. Click the drop-down arrow, and choose Add New.
4. Enter the Name of the payment term and number of days.
5. Then hit Save.

I've also added this article for more details on editing and setting up payment terms in QuickBooks Online: How to Adjust Invoice Payment Terms in QuickBooks Online. It may be from another region, but the process is the same. 

Moreover, you can check these articles for future reference:

• Customise invoices, estimates, and sales receipts in QuickBooks Online
• Record invoice payments in QuickBooks Online

I'll be here if you need anything else or clarification with managing invoices in QBO. Take care always!