Grey route
What is Grey route?
A grey route is a messaging path that delivers application-to-person traffic over a channel intended for person-to-person messages — bypassing a carrier's official A2P commercial agreements, fees, and registration requirements — to send at a lower cost than legitimate routes allow. Grey routing violates carrier terms and is a primary target of carrier SMS firewalls; traffic caught on a grey route is typically blocked outright, and a business whose messages are found in a grey channel risks its sender reputation across legitimate routes too.
More detail
Grey routes often appear cheaper precisely because they skip the licensing fees and registration overhead of legitimate A2P routes — a price difference that's itself a red flag for buyers evaluating a messaging vendor.
A reputable messaging platform sends exclusively over licensed, carrier-approved routes and avoids grey-route aggregators, since the short-term cost savings carry a high risk of sudden, unannounced blocking.
Frequently asked
- Why would a messaging vendor's pricing be suspiciously cheap?
- An unusually low SMS rate can indicate the vendor is routing traffic through grey routes that skip legitimate carrier fees and registration — a practice that risks sudden blocking and violates carrier terms, regardless of how the price is marketed.
- What's the risk of sending A2P traffic over a grey route?
- Grey-route traffic is a primary target of carrier SMS firewalls and is typically blocked outright once detected, and it can damage a sender's reputation on legitimate routes even after they stop using it.
See also
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