user4418: The FIDE Handbook has a section called Regulations on Seminars & Title Award for Organizers where it describes what you need to do to get the FIDE International Organizer title. It says:

Scope / Mission: To get the FIDE licence for the organisation of FIDE,
  Continental and International tournaments.

Now, I know that the title is not a requirement to organize a low level FIDE rated tournament because I have done so in my club along with another player who also has no organizer title.
My question is: is it a requirement for high level tournaments and if so, where is the border between requiring the title and not needing it?

user4418: It looks like the answer is "No" because Arkady Dvorkovich, who has no organizer title, was the chief organizer for the FIDE Grand Prix Series Riga- 2019, FIDE Grand Prix Series Riga- 2019 Blitz Tie-breaks and FIDE Grand Prix Series 2019 Rapid Tie-breaks tournaments.
However there is an additional paid position for "FIDE World Events" called a "FIDE Technical Director". The role is described here.


FIDE Technical Director (FTD) is the overall observer of a FIDE
  World Event
The FIDE Technical Director FTD is appointed by FIDE and must be a licensed International Organizer
Main duties of the FIDE Technical Director"   
  
  
To be responsible for the communication with the Organizer after the approval and circulation of the tournament regulations.
To check before the start of the competition if the organization adheres to FIDE standards.
To check if the Organizer provides to the participants the conditions offered in the bid and described in the event invitation.
To be contacted by the National Federations as the FIDE Representative.
To ensure the contact of the competitions according to FIDE rules and regulations
By the end of the competition to send his report to FIDE including and comparing the final evaluation with the bid-evaluation.

Organizer provides the following conditions to the FIDE Technical Director:
  
  
Single room (FB- 3 meals) 2 days before the start of the competition till departure
Air-travel expenses & transportation to the venue

FIDE pays to the FIDE Technical Director the stipend in accordance with the Financial Guidelines for the Technical Officials.



4418: <p>The FIDE Handbook has a section called <a href="https://old.fide.com/component/handbook/?id=48&amp;view=category" rel="nofollow noreferrer">Regulations on Seminars &amp; Title Award for Organizers</a> where it describes what you need to do to get the FIDE International Organizer title. It says:</p>

<blockquote>
  <p>Scope / Mission: To get the FIDE licence for the organisation of FIDE,
  Continental and International tournaments.</p>
</blockquote>

<p>Now, I know that the title is not a requirement to organize a low level FIDE rated tournament because I have done so in my club along with another player who also has no organizer title.</p>

<p>My question is: is it a requirement for high level tournaments and if so, where is the border between requiring the title and not needing it?</p>
 4418: <p>It looks like the answer is "No" because <a href="https://ratings.fide.com/card.phtml?event=34404449" rel="nofollow noreferrer">Arkady Dvorkovich</a>, who has no organizer title, was the chief organizer for the <a href="https://ratings.fide.com/tournament_details.phtml?event=222540" rel="nofollow noreferrer">FIDE Grand Prix Series Riga- 2019</a>, <a href="https://ratings.fide.com/tournament_details.phtml?event=225311" rel="nofollow noreferrer">FIDE Grand Prix Series Riga- 2019 Blitz Tie-breaks</a> and <a href="https://ratings.fide.com/tournament_details.phtml?event=222541" rel="nofollow noreferrer">FIDE Grand Prix Series 2019 Rapid Tie-breaks</a> tournaments.</p>

<p>However there is an additional <em>paid</em> position for "FIDE World Events" called a "FIDE Technical Director". The role is described <a href="https://old.fide.com/component/handbook/?id=49&amp;view=category" rel="nofollow noreferrer">here</a>.</p>

<blockquote>
  <ol>
  <li>FIDE Technical Director (FTD) is the overall observer of a FIDE
  World Event</li>
  <li>The FIDE Technical Director FTD is appointed by FIDE and must be a licensed International Organizer</li>
  <li>Main duties of the FIDE Technical Director"   
  
  <ul>
  <li>To be responsible for the communication with the Organizer after the approval and circulation of the tournament regulations.</li>
  <li>To check before the start of the competition if the organization adheres to FIDE standards.</li>
  <li>To check if the Organizer provides to the participants the conditions offered in the bid and described in the event invitation.</li>
  <li>To be contacted by the National Federations as the FIDE Representative.</li>
  <li>To ensure the contact of the competitions according to FIDE rules and regulations</li>
  <li>By the end of the competition to send his report to FIDE including and comparing the final evaluation with the bid-evaluation.</li>
  </ul></li>
  <li>Organizer provides the following conditions to the FIDE Technical Director:
  
  <ul>
  <li>Single room (FB- 3 meals) 2 days before the start of the competition till departure</li>
  <li>Air-travel expenses &amp; transportation to the venue</li>
  </ul></li>
  <li>FIDE pays to the FIDE Technical Director the stipend in accordance with the Financial Guidelines for the Technical Officials.</li>
  </ol>
</blockquote>
