Everything worth knowing, nothing that isn't.
How omnichannel messaging works
You send a message to a customer through a single API; the platform resolves which channels the recipient can receive, applies your priority and cost rules, and delivers over the best one — falling back automatically if it isn't delivered. A unified thread stitches replies from every channel into one conversation, so an SMS OTP, a WhatsApp reply, and an email receipt all belong to the same customer record. See /products/omnichannel and /answers/what-is-omnichannel-messaging.
The channels it spans
SMS for universal reach; WhatsApp for rich, two-way conversation where the app is installed; RCS Business Messaging for branded, interactive native messaging; voice for calls and voice OTP; and email for long-form and receipts. Each has different reach, cost, and interactivity, which is exactly why routing across them beats committing to one. See /answers/rcs-business-messaging, /answers/what-is-whatsapp-business-api, and /answers/email-deliverability.
Channel selection and failover
The routing engine picks a channel by rules you set — cheapest-that-reaches, richest-that-reaches, or a fixed cascade like WhatsApp then SMS then voice for a verification code. If the primary isn't confirmed delivered within a window, it fails over to the next, and you are billed once for the outcome, not once per attempt. This lifts delivery rates while controlling spend. See /answers/what-is-route-failover and /answers/number-verification.
Benefits over single-channel messaging
Higher delivery through automatic fallback, lower cost by routing to the cheapest channel that reaches, a consistent branded experience across touchpoints, one integration instead of five, and a single customer conversation history for support and analytics. It turns disconnected channel silos into one coherent communications layer. See /answers/what-is-cpaas and /products/omnichannel.
Limitations and what to plan for
Each channel keeps its own rules — WhatsApp's 24-hour window and template approval, RCS device and carrier coverage, SMS sender-ID registration — so an omnichannel strategy must respect all of them, not paper over them. Encrypted OTT channels also sit outside SMS-firewall visibility, and per-channel pricing differs, so cost modelling matters. See /answers/whatsapp-24-hour-window and /answers/what-is-ott-bypass.
Is omnichannel the same as multichannel messaging?
No. Multichannel means you offer several channels, but each runs as its own silo with a separate thread. Omnichannel unifies them: one API, one customer conversation, and automatic routing and failover between channels. The practical difference is continuity — in omnichannel a customer who switches from SMS to WhatsApp mid-conversation stays in the same thread. See /answers/what-is-omnichannel-messaging.