Resources
Two-way messaging from your own numbers
Send SMS and MMS from your CarrierX numbers with one API call, and receive replies in your application as HTTP callbacks. Messages can go out on local 10DLC numbers or on toll‑free numbers.
Your business: Northwind: Your order has shipped and arrives Thursday. Reply HELP for help, STOP to opt out.
Sent with one API call
Customer: Can I change the delivery address?
Delivered to your app as an HTTP callback
Your business: Yes. Reply with the new address and we will update your order.
Delivery status reported back
Why it matters
How two-way messaging works
Sending takes one API call. When someone texts your number, CarrierX makes an HTTP call to your application with the details, and it reports the status of the messages you sent.
Two-way by design
Replies arrive in your application as they come in, so a notification can turn into a conversation.
SMS and MMS, one API
The CarrierX API largely abstracts away the difference between text and multimedia messages, which keeps your code simpler.
Local or toll‑free
Send from local 10DLC numbers or from toll‑free numbers, each with its own registration.
Use cases
What businesses send
SMS suits short, text-only messages. MMS carries images, audio and video, and reaches groups.
Two-factor codesSMS
One-time codes sent to confirm a sign-in.
Delivery notificationsSMS
Order and shipping updates that customers can reply to.
Emergency alertsSMS
Short, urgent notices sent to the people affected.
Marketing and newsMMS
Promotions, news and entertainment with images, audio or video attached.
Group messagesMMS
One message sent to a group of recipients.
Number types
Long code or toll‑free
Both carry two-way SMS and MMS. They differ in how they look to recipients, how fast they send, and how they are registered.
| Long code (10DLC) | Toll‑free | |
|---|---|---|
| Looks like | A regular 10-digit number that recipients see as local | An 8xx number, long associated with established companies |
| Throughput | Varies with brand and content | High |
| Registration | A brand review, then a review for each campaign | One Verified Sender Request; a relatively simple review |
| Typical approval | Around 3 business days for simple campaigns; up to a couple of weeks for complex ones | Generally 5 to 10 business days |
| Numbers | Several numbers can be pooled; identify the pool in advance at 50 or more | One number per business location; no pooling |
| Per-message cost | Lowest | Higher than long code |
Short codes, 5 or 6 digits long, are a third option with the highest throughput, reviewed by each mobile operator.
Features
What CarrierX gives you
One messaging API for both number types, and registration that runs through your CarrierX representative.
SMS-enabled numbers
Rent numbers in the CarrierX Portal or through the API, and enable messaging on each one under a campaign.
Messaging API
Send an SMS or MMS from your number with one API call.
Inbound callbacks
Messages sent to your number reach your application as HTTP callbacks.
Delivery status
CarrierX reports the status of the messages you send.
Automatic segmenting
CarrierX handles the character set, message concatenation and queuing for you.
Registration support
CarrierX helps you understand the requirements for 10DLC and toll‑free registration.
Questions
Common questions
Programmable messaging
Choose the right numbers for your messages
Book a call with the CarrierX team to go through what you send, who you send it to, and which number type fits.