How do I set up a product service item that is billed monthly to a customer? I am using Quickbooks Simple Start. Can this be set up as a recurring service for invoices?

Good day, @grant-mankaidigi.

The option to create recurring transactions is unavailable in QuickBooks Online (QBO) Simple Start. 

This feature is offered in QBO Essential and Plus versions. If you wish to upgrade your subscription, here's how: 

1. Sign in to QBO as a primary or company admin.
2. Go to Settings ⚙, then click Account and settings.
3. Select the Billing & Subscription tab.
4. Make sure your payment info is up-to-date.
5. In the QuickBooks Online section, select Upgrade your plan.
6. Review the available plans and click Choose plan.
7. Follow the on-screen steps to upgrade your plan.

In the meantime, you can manually record the transactions when billing your customers. 

Moreover, check out the available pricing plans to see which subscription level is right for you.

You're welcome to visit this thread again if you have questions regarding QuickBooks Online, @grant-mankaidigi. I'm always here to assist you.