US carriers treat a ten-digit local number sending business traffic differently from one in a person's hand. Registration is how that traffic becomes declared rather than inferred. It is the difference between messages that arrive and messages that get filtered.

## What is being registered?

Two things, in order, and then the numbers.

A **brand** is the business. It carries the legal identity of who is sending, which is what a carrier needs to attribute traffic to a real company rather than an account.

A **campaign** is the traffic. It declares what kind of messages will be sent, how recipients opted in, and what they can expect. A carrier evaluates that declaration when deciding how to treat the volume.

Numbers then attach to the campaign. That order matters because a number's permission to send derives from the campaign it belongs to rather than from the brand. One business can hold several campaigns, each with its own traffic and its own numbers.

## When can the numbers actually send?

Later than when they are assigned.

Assignment and permission are two moments. Numbers can be assigned to a campaign while it is still pending. They begin sending once the campaign is approved and the carriers confirm each number individually. So a successful assignment call is not a signal that traffic will flow.

Bird's own send path checks the sender's registration before accepting a message, so where a destination requires registration the send is refused rather than attempted.

## What limits apply before you start?

A campaign size and an exclusivity rule, both of which shape how you group numbers.

A campaign holds up to 49 numbers, and a number belongs to one campaign at a time. Together those mean a fiftieth number needs a second campaign rather than a larger one. Moving a number between campaigns is a move rather than an addition.

Assignment is also all or nothing. Either every number in a request is assigned or none is. A batch containing one ineligible number leaves the whole batch unassigned rather than partially applied.

## Is this the same as registering any other sender?

No. It is one program among several, and none of them substitutes for another.

| Route                  | What it covers                                       |
| ---------------------- | ---------------------------------------------------- |
| 10DLC                  | US business traffic on ten-digit local numbers       |
| Toll-free verification | US and Canadian toll-free numbers used for messaging |
| Short-code application | US short codes, applied for rather than bought       |
| Country registration   | Sender identities in countries that require one      |

General country registration refuses senders that belong to a dedicated program, so a US long code cannot be registered through it. [Sender ID registration](/explained/sms/what-is-sender-id-registration) covers the country route and which program applies to a given sender. [Which sender type should I use](/explained/sms/which-sms-sender-type-should-i-use) covers choosing between number types in the first place.

## How do I run it on Bird?

Through the dashboard or the CLI, brand first, then campaign, then numbers.

You create a brand, then a campaign under it, then assign your US long codes to that campaign. Those are dashboard and command-line surfaces rather than public API operations. Build the flow around the [10DLC guide](/docs/guides/sms/10dlc) rather than around a public endpoint.

Registration also has costs attached that are separate from per-message pricing. The Campaign Registry levies the brand and campaign registration fees, including the recurring campaign fee. [SMS carrier fees and surcharges](/explained/sms/what-are-sms-carrier-fees-and-surcharges) covers how those appear.

## Related resources

- [SMS numbers](/products/sms/numbers) (product)
- [Number types](/docs/guides/numbers/number-types) (docs)
- [What is a virtual phone number (VMN)?](/explained/numbers/what-is-a-virtual-phone-number) (answer)

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