# SMS routing: destinations, carrier paths and delivery receipts The route behind your message Sending workflow Your application Choose the recipient, sender, category and message. Destination and sender checks Use an enabled market and the required registration. Carrier handoff Bird submits the message through its carrier connections. A reported outcome Follow the receipt in message records, webhooks and analytics. A conceptual flow. Acceptance, carrier handoff and a delivery receipt describe different stages of the message lifecycle. ## The layer your send rides on. Routing sits beneath the [Bird SMS API](/sms-api). Bird checks the destination and sender before acceptance, then submits the prepared message to its carrier transport. Inspect the reported carrier and outcome when deciding whether to investigate a sender, destination or recipient issue. ## Understand the decisions before carrier handoff. Eligibility, message preparation and carrier submission have distinct roles. - **01** Carrier connectivity. Bird manages the carrier connections behind your send. Use the destination catalogue to check supported sender types and registration requirements for the markets you serve. - **02** A prepared sender and destination. Sender type, destination rules and registration determine which originator can be used. A valid setup is established before the message is queued for transport. - **03** Operator information when available. Processing can resolve the recipient's operator for pricing. A missing or failed lookup falls back to country pricing. Carrier information in a receipt may also be absent; avoid inferring a network from the phone prefix alone. - **04** Delivery receipts as carrier evidence. A carrier receipt can report delivery or a terminal non-delivery outcome. Some messages remain awaiting a receipt, and missing carrier fields are unknown. Read the event timeline alongside the current status. - **05** Discuss route requirements for a rollout. The public SMS request does not offer a least-cost versus highest-quality route selector. Discuss destination mix, sender requirements and throughput with an SMS specialist when planning larger traffic. ## A delivery outcome you can investigate. A successful SMS journey depends on the destination, sender registration, message content and carrier path. Bird brings those decisions into one sending workflow. Start with the destination's requirements, then use message records and carrier outcomes to identify what needs to change. ## Routing leans on number intelligence. Use [Lookup](/lookup-api) when your application needs supported phone-number intelligence. Subscribe to [webhooks](/docs/guides/webhooks) for SMS outcomes and use the [error reference](/docs/guides/errors) and [deliverability guide](/docs/guides/deliverability) to interpret reported failures. A lookup result does not establish sender eligibility or guarantee delivery. ## Questions before you build ### How do I check destination coverage? Open the destination catalogue and review the sender types and registration requirements for each market. Your workspace must also allow the destination before a send is accepted. ### What does a carrier receipt establish? It reports a delivery outcome from the carrier. Receipts can arrive after acceptance, and the message record may still be pending. Delivery does not measure whether someone read or acted on a text. ### How should I investigate a failed route? Start with the message status and failure reason. Compare reporting by carrier, country or sender, then check registration and destination configuration. An aggregate failure rate alone does not identify the cause. ### Can I inspect a phone number separately? Use Lookup when your application needs phone-number intelligence before sending. Review the signals and availability for that lookup rather than treating an SMS delivery report as a complete number check. ## The rest of the SMS platform One API, one set of keys. Explore the other capabilities. - [Sending](/sms-api/features/sending): The send API: segments, Unicode safety, batch, and idempotency. - [Numbers](/sms-api/features/numbers): Long codes, short codes, toll-free, and alphanumeric sender IDs. - [Two-way](/sms-api/features/two-way): Inbound SMS and conversational replies as HMAC-signed webhooks. - [Compliance](/sms-api/features/compliance): A2P 10DLC registration, opt-out keywords and sender-ID rules. - [Analytics](/sms-api/features/analytics): Delivery outcomes, failure reasons and latency from carrier receipts. - [SMS API overview](/sms-api): The full SMS API: sending, numbers, two-way, compliance, routing, and analytics. - [SMS resource library](/sms-api/resources): Find guides, explained answers and tools for your next step. ## Scale without losing control. Organize teams in workspaces, control API access, and trace changes through audit logs. Harbor Organization Workspaces Production Sandbox ### Delivery agent API key · Customer operations team Active Permissions Access Email Read & write SMS Read & write WhatsApp Read Read & write AL Alex Lee Admin Permissions updated ### Audit log Production API key updated Alex Lee · 09:42:18 UTC Workspace Production Resource Delivery agent WhatsApp Read Read & write Succeeded [Workspaces](/docs/guides/workspaces)[Team roles](/docs/guides/users-teams-roles)[API authentication](/docs/guides/authentication) [Explore Enterprise](/enterprise) ## Start with SMS. Build across channels with Bird. [Get started](/dashboard/signup?returnTo=%2Fdashboard%2Fw%2Fsms%2Fonboarding) · [Contact Sales](/demo?product=sms) [Email](/email-api) · [SMS](/sms-api) · [WhatsApp](/whatsapp-api) · [Apple Messages](/apple-messages-api) · [Voice](/voice-api) ## Related resources - [SMS tracking and metrics](/docs/guides/sms/tracking-and-metrics) (docs) - [What does a delivery receipt tell you?](/explained/sms/what-is-a-delivery-receipt) (answer) - [Operate messaging reliably](/learn/paths/reliability) (course) [Get an implementation brief](/learn/workspace?topic=sms-reporting)