What should an A2P 10DLC delivery verification checklist include?

10DLC is the US framework for application-to-person messaging over standard 10-digit long codes. Carriers expect every sender to register a brand and at least one campaign that describes the use case, such as account notifications or two-factor codes. Registration happens through your messaging provider, and it is your responsibility as the sender.

Check that the numbers you send from are attached to the approved campaign, that the message content matches the declared use case, and that sample messages in the registration look like the real ones. A mismatch between declared and actual content is a common reason for filtering.

Keep consent records for every recipient, answer STOP and HELP correctly, and identify your brand in the message. Put links on a domain you control; many carrier and industry guidelines discourage shared public link shorteners.

Registration makes filtering less likely; it does not prove delivery. The second half of the checklist is observation on a real US number: whether each message arrived or was not observed inside a time window, how long it took, which sender or brand the phone displayed, whether the content arrived unchanged, and whether the link in the message is present and intact.

This observation is what lets you tell "my system never sent it" apart from "it was sent and did not arrive". It also gives you neutral evidence to share with your provider. What it cannot do is prove why a carrier filtered a message: without specific evidence, nobody should claim that a carrier blocked it.

A2P / 10DLC Delivery Verification is coming soon. It requires a real SIM with a US number, and that SIM is not installed yet; the probe is not built and there are no backtests or real samples, so nothing is published. The product stays unavailable until real evidence exists.

When it ships, you will send A2P messages from your own platform to an authorized US number and declare the expected brand or sender and a correlation window. On a shared receiving number, each message must carry your correlation token of 6-32 letters, digits or hyphens in the body; a token already used by another customer is rejected. Each message will produce a run with received or not observed, latency, sender, content integrity, link presence and signed evidence, kept 90 days.

Witnio will not register your brand or campaign and will not send messages for you. Until the US corridor is served, OTP/SMS monitoring on an international number covers the same delivery questions.