Organisation providing a particular service (6)
I believe the answer is:
agency
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">organisation providing a particular service</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for agency that I've seen before include "Office or business of one who does business for others" , "Government office" , "Travel ..., advertising..., employment" , "Business providing specific service" , "Government unit - business providing services" .)