Athens – Piraeus Urban Society of Customs Brokers or Urban Society of Customs Brokers of Piraeus and Athens

See:

«Αστική Εταιρεία Εκτελωνιστών» Πειραιώς – Αθηνών

http://www.sepa.com.gr/component/content/article/915-eepa-af...

The CSCB (Canadian Society of Customs Brokers) actively seeks and achieves improvements in government policies and procedures on behalf of our members ..
http://cscb.ca/content/about-us

http://financial-dictionary.thefreedictionary.com/Customs Ho...
.
https://en.wikipedia.org/wiki/Customs_broking


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Note added at 1 day3 hrs (2015-12-21 11:55:06 GMT)
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Alternatively, you could say, “Customs Brokers Society of the Cities of Piraeus and Athens”, or, “Customs Brokers Society of Piraeus and Athens”, which both sound better in English than “Urban Customs Brokers Society of Piraeus and Athens”.

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Note added at 1 day20 hrs (2015-12-22 04:57:51 GMT)
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The CSCB (Canadian Society of Customs Brokers) reference is naturally only given to confirm that the term "Society of Customs Brokers" or "Customs Brokers Society" is used in English.

Also see:

2 days ago - ... contact the Customs Brokers and Freight Forwarders Association of Jamaica (CBFFAJ), or the Customs Brokers Society of Jamaica (CBSJ).
http://www.jamaicaobserver.com/news/clearing-customs/

or

29 Apr 2015 - ... Management Students (SHOREMS). 9. Association of Fisheries Students (AFS). 10.Chamber of Junior Customs Brokers Society (CJCBS)
http://newwashington.asu.edu.ph/index.php/academic/office-of...