Add a custom text with tax / legal terms on invoices

We would like to add a text (e.g. with taxation terms) on our invoices as the very last paragraph directly before the signature. Please advise.

You can easily add such a text at the described position. Please go to:
Overview => Settings => Wording and Phrases

Search for the following string “S_INVOICE_APPENDIX”. Edit this phrase and enter your text.
Please take a look at the position of the new item in the image below.

If you want to add a header or footer text, or payment terms just below the invoice table, you have the following options:

Please open the settings for participant registration here:
Overview => Settings => Main Settings for Participant Registration

You can enter further information as text in the "Extra header for invoices (optional)" which will be put at the very top of the invoice, and the "Extra footer for the invoices (optional)", which will appear on the bottom of the page.

For payment terms and conditions or legal terms regarding the payments, you can add another line of text directly beneath the invoice table with the items and prices. Activate the expert settings by clicking on "Expert Settings" / the cogwheel at the bottom of the screen.
The new option "Legal Clause for Invoices" appears and you can now enter further text.

The positions of these items are pictured in the image below.