Law firms, claims teams, and hospitals rarely select interpreters one by one. They select an interpreting agency, and the agency selects everyone who shows up after that. The seven checks below take about twenty minutes per candidate agency, and they predict almost everything that matters: whether the interpreter who appears is actually credentialed, whether the record survives a challenge, and whether anyone answers the phone when an assignment moves.
Define the credential tier your matter requires
Different settings carry different credential standards, and the first sign of a serious agency is that it asks about the setting before quoting. Courtroom and deposition work calls for a certified court interpreter, or a registered interpreter in languages where no certification exam exists. Medical encounters call for CCHI or NBCMI credentialed interpreters. Sign language work calls for RID certification. California workers' compensation has its own standard under 8 CCR section 9795.1.5. An agency that quotes a flat answer without asking what the proceeding is has already failed the first test.
Ask how credentials are verified and documented
Certification claims are checkable against public rosters, and a professional agency checks them before you have to. Ask whether the confirmation you receive will name the interpreter and state the credential, and ask what documentation you would receive if opposing counsel challenged the interpreter's qualification on the record. The full verification walkthrough is in how to verify an interpreter's credential.
Match subject-matter experience, not just the language pair
An interpreter can be fully certified and still be the wrong fit. An IME runs differently from a deposition; an examination under oath has its own rhythm and claims vocabulary; family court testimony demands a temperament that not every courtroom veteran has. Ask how the agency matches interpreters to the proceeding type, and ask for an example: which of their interpreters covers neuropsychological evaluations, and why that one.
Ask how conflicts of interest are screened
Any agency with real volume eventually serves both sides of the same dispute. The question is whether it notices. Ask whether the agency keeps conflict logs, whether the same interpreter can be assigned to both sides of an active matter, and what happens when an interpreter discloses prior contact with a party or witness. The credible answer involves a log, a disclosure rule, and a substitution.
Confirm team interpreting for long proceedings
Interpreting accuracy degrades measurably with fatigue, which is why NAJIT guidance calls for a two-interpreter team on proceedings that run beyond about an hour. An agency that proposes a single interpreter for a full-day trial or arbitration is either unaware of the standard or hoping you are. The background is in interpreter teams for long proceedings.
Check the document translation QA process
If the engagement includes translation, ask who reviews the work. The professional standard is a second, independent native-level linguist reviewing every project before delivery, plus a signed certificate of accuracy where the destination requires one. For immigration filings, the agency should know 8 CFR 103.2(b)(3) without looking it up; the distinction is covered in certified vs. notarized translation.
Pressure-test scheduling, backup, and billing
Ask three operational questions. What happens when an interpreter cancels the night before a deposition? Can the agency take a request after hours, and at what premium, if any? And does the invoice itemize interpreter, time, and proceeding so it can survive a client audit or a cost bill? On the last point, remember that in California only a certified or registered interpreter's fees are recoverable as costs, as explained in deposition interpreter fees and cost recovery.
A good agency answers all seven without hesitation, in writing. That is the standard AMS holds itself to: certified and registered interpreters confirmed by name and credential before every assignment, conflict logs, NAJIT-consistent team staffing, and second-linguist review on every translation. See our representative clients or request a quote to test the checklist on us.