Bureau of Customs vs Customs Service

Bureau of Customs and Customs Service both are nouns.

Word	Noun	Adjective	Verb	Adverb
Bureau of Customs	Yes	No	No	No
Customs Service	Yes	No	No	No

As nouns, Bureau of Customs and Customs Service are synonyms defined as:

Bureau of Customs and Customs Service: the agency of the Treasury Department that enforces import tariffs

Other synonyms of Bureau of Customs include Customs Bureau, USCB.

Bureau of Customs (noun)	Customs Service (noun)
the agency of the Treasury Department that enforces import tariffs	the agency of the Treasury Department that enforces import tariffs