Go to the "Configuration" => "Invoice Tags".

Invoice tags list view, here you can create tags.

Invoice list view with tags.

Invoice form view with tags.

Invoice kanban view with tags.

You can search tags from the search view in the invoices.

The search tags result in the invoices.

You can search tags from the search view in the credit notes.

The search tags result in the credit notes.

You can search tags from the search view in the bills.

The search tags result in the bills.

You can search tags from the search view in the refunds.

The search tags result in the refunds.

You can enable/disable tags fields in the invoices tree view.

You can enable/disable tags fields in the credit notes tree view.

You can enable/disable tags fields in the bills tree view.

You can enable/disable tags fields in the refunds tree view.

Update mass tags access rights.

Select tags from the list view and click "Update Mass Tag".

After that one wizard opens, select update method and tags then press the "Done" button to update tags.

Default tags configuration.

Default tags auto added in form view.