I noticed, on YouTube, that Trey Gowdy in his congressional confrontations used the word 'purview' but never 'remit'. I could not find 'remit' as a noun in Merriam Webster, only the verb, and wondered if the sense of 'remit' as 'scope of responsibility' is maybe BrE not AmE.
Then I found, indeed, that OED gives :
b. Chiefly Brit. A set of instructions, a brief; an area of authority or responsibility. Frequently in within (also beyond, etc.) one's remit.
Presumably AmE has no use for 'remit' perhaps ?
Or does BrE distinguish in usage between 'remit' and 'purview' ?
Purview , noun, 2. In extended use: the scope or limits of anything (as a document, inquiry, scheme, subject, occupation, etc.); remit; intent.
[Note: The other noun from 'remit' is 'remittance' but has an entirely different meaning to 'remit'.]
Best Answer
Following up on user2922582's answer, I note that The American Heritage Dictionary of the English Language, fifth edition (2011) has the same two definitions for remit as a noun that appear in the online AHDEL:
Merriam-Webster Online, too, has taken notice of the British English sense of the term:
These appear to be relatively recent developments, however. For example, The American Heritage Dictionary of the English Language, fourth edition (2001) has a significntly different pair of entries for remit as a noun:
And two other U.S. dictionaries of similar vintage show similar ignorance of (or disregard for) remit in the "chiefly British" sense. From Encarta World English Dictionary (1999):
(I might mention here that in the many U.S. judicial opinions I read during three years of law school, the usual term for the act of returning a case to a lower court for further action was remand, not remit.) And from Merriam-Webster's Eleventh Collegiate Dictionary (2003):
My copy of the massive and unabridged Webster's Third New International Dictionary (1961/1986) has an even narrower definition of the noun remit:
The Oxford American Dictionary and Thesaurus (2003) comes closer to including the AHDEL's "chiefly British" meaning at a somewhat earlier date, although the wording of the first definition is so vague that I am unsure how close it actually is to that meaning:
If "terms of reference" in definition 1 of this entry means something like "claimed ambit of responsibility," then this definitions is quite close to AHDEL 5's definition 2—but it isn't clear to me that the phrase has that particular meaning.
Conclusion
Even 15 years ago, U.S. English dictionaries showed very little awareness of remit in the sense of "an area of responsibility." That has changed within the past decade, but even now, U.S. usage of remit in the chiefly British sense does not appear to be widespread. And with the rise of "beyond my pay grade" as an alternative to saying "not within my remit," there doesn't seem to be much of a groundswell in popular U.S. usage toward increased adoption of remit to mean "purview, scope, or area of responsibility."