Foreign  firms  may  provide  tax  advisory  services  (conseil  fiscal)  on  the same  basis  as  Tunisian  nationals,  provided  that  Tunisian  professionals  enjoy  the  same opportunities, de jure and de facto, in their home countries.
"Art. 2. - No one can make the profession of tax adviser, if he has not been approved by the Secretary of State for Finance and Commerce.
[...]
Art. 3. - The approval referred to in article 2 above can only be granted to persons fulfilling the following conditions:
1. be of Tunisian nationality for at least five years;
[...]
Art. 5. - Foreign natural persons and foreign companies may be admitted to exercise, in Tunisia, the profession of tax advisor, under the conditions provided for by this law, provided that in the country to which they belong, Tunisian natural persons or companies benefit, in law and in fact, from the same faculty.[...]" (Law on the approval of tax advisers (n° 60-34 of 14 December 1960), Articles 2, 3 and 5 [google translation])
Law on the approval of tax advisers (n° 60-34 of 14 December 1960), Articles 2, 3 and 5
[<a href="https://www.pist.tn/record/117857?ln=fr">Law</a>]