I can´t see TAGS. I'm running simple start plan. Does it has to be with plan limitations? What plan includes Tags? Where can I see a detailed list of all plan features?

Welcome to the Community, @fernandobartolom.

You can use TAGS even on the Simple Start plan. You can enable that feature via QuickBooks Labs.

To turn it on:

1. Go to Settings ⚙ and select QuickBooks Labs.
2. Look for the Tags feature and turn it on.
3. Click Done

You can now go to Settings ⚙ and under Lists, Tags should be available.

You can use these articles to get started with tags: 

• Tag transactions in QuickBooks Online
• How to use tags

To know more about QuickBooks Online and its features per plan - here's the QBSE, QBO comparison chart.

If you have other questions, feel free to drop a comment and I'd be glad to help.