What Does ISO 17100 Certification Actually Mean?
ISO 17100 is the international standard written specifically for translation services (as opposed to ISO 9001, which is a general quality-management standard that applies to any business). In practical terms, it requires a translation provider to follow a defined process for every project: translation by a qualified linguist, followed by a review/edit by a second qualified linguist (this is the "TEP" process — Translate, Edit, Proofread), plus documented requirements for translator qualifications (either a recognized translation degree, an equivalent qualification plus experience, or a minimum number of years of documented translation experience).
In short: ISO 17100 certification means a translation did not pass through only one person's eyes before being delivered, and that the people involved meet a defined minimum qualification bar — not just a claim of "professional translators" with no process behind it.