Hey @GavinSP,

I appreciate your effort in reaching out to our phone support. Let me provide additional details about this to help you further.

QuickBooks is working based on how it was designed by our developers. 

When you print your invoice, the items on the preview are based on how you entered them. If you entered them in a specific order, they should also appear the same way. 

Also, the service dates for your items will be sorted according to the dates in descending order. 

In the meantime, you may want to enter service dates your invoice items to sort them correctly. You may refer to the screenshot below about how your invoice would appear with service dates.

If you have further questions or concerns, please reach out to me. I'll be here in the Community to help you.