How can I delete unused Products or Services in the drop-down menu of the Invoice template? I want to reduce the chance of an error.

It's a pleasure to have you here today, sullyman. I've got some details about managing product and services in QuickBooks Self-Employed (QBSE).

In QBSE, the ability to delete products or services is currently unavailable. You may want to explore QuickBooks Online for more invoice customization options, like adding and deleting products and services. This version offers more advanced features in this area.

Moreover, we aim to maintain a user-friendly program that meets the specific needs of each business. Introducing a feature that deletes unused products or services would surely benefit them. Let's forward this product suggestion to our engineers for consideration in future releases.

Here's how:

1. Open your QBSE mobile application.
2. Tap the + button, then the Assistant icon.
3. Type feedback in the field.
4. Choose Add a feature.
5. Enter and send your product suggestions.

On the other hand, if you need help managing and paying your estimated taxes in the future, check out this article for more details: Pay federal estimated quarterly taxes in QuickBooks Self-Employed. 

I'm happy that you've visited the Community space today, sullyman. Let me know if you have other concerns about managing your product or services or other question using QBSE, add the details to your reply and I'll help you out.