> ## Documentation Index
> Fetch the complete documentation index at: https://developers.phonovation.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Sender IDs

> Understand API Sender ID rules, ComReg registration, longcodes, and international delivery.

A Sender ID is the name or number placed in the campaign's `from` field and shown to the recipient. Before you can send with it, the Sender ID must be permitted for the destination and assigned to your Phonovation account.

<Warning>
  If you use an alphanumeric Sender ID to deliver application-to-person SMS to Irish mobile numbers, you must register it with ComReg. Unregistered Sender IDs may be changed to `Likely Scam` and may later be blocked.
</Warning>

```mermaid title="Set up a Sender ID" theme={"dark"}
%%{init: {"theme": "base", "themeVariables": {"fontFamily": "Outfit", "fontSize": "16px", "primaryColor": "#fff1ef", "primaryTextColor": "#0f1926", "primaryBorderColor": "#d23a25", "lineColor": "#4b69a0", "secondaryColor": "#eaf0fa", "tertiaryColor": "#edf8f0"}}}%%
flowchart TD
  Start["Where will you send?"] --> Irish{"Irish mobile numbers?"}
  Irish -->|"No"| International["Ask Phonovation Support about local rules"]
  Irish -->|"Yes"| Type{"Alphanumeric Sender ID?"}
  Type -->|"No — use a longcode"| Sales["Contact Sales to purchase and provision it"]
  Type -->|"Yes"| Registered{"Registered with ComReg?"}
  Registered -->|"No"| ComReg["Register as a SIDO and register the Sender ID"]
  Registered -->|"Yes"| Review["Review it in My Sender IDs"]
  ComReg --> OPA["Select Phonovation as the OPA"]
  Review --> OPA
  OPA --> Support["Email Phonovation Support"]
  Support --> Account["Phonovation assigns it to your account"]
  Account --> Send["Use it in the from field"]

  classDef decision fill:#eaf0fa,stroke:#4b69a0,color:#0f1926,stroke-width:2px
  classDef action fill:#fff1ef,stroke:#d23a25,color:#0f1926,stroke-width:2px
  classDef ready fill:#edf8f0,stroke:#247a4b,color:#0f1926,stroke-width:2px
  class Start,Irish,Type,Registered decision
  class International,Sales,ComReg,Review,OPA,Support,Account action
  class Send ready
```

## ComReg and the registry

ComReg is Ireland's Commission for Communications Regulation. Its [SMS Sender ID Registry](https://www.comreg.ie/industry/electronic-communications/nuisance-communications/sms-sender-id-registry/) records the organisations, Sender IDs, and SMS providers permitted to originate alphanumeric Sender IDs for Irish mobile recipients.

| Term            | Meaning                                                                                                                                                                                             |
| --------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **SIDO**        | The Sender ID Owner: the organisation that holds the right to use the Sender ID. Your organisation is normally the SIDO for its own brand.                                                          |
| **PA**          | A Participating Aggregator registered with ComReg to carry SMS containing registered Sender IDs.                                                                                                    |
| **OPA**         | The Originating Participating Aggregator: the SMS provider responsible for transmitting your messages. When you send through Phonovation, select **Phonovation** as the OPA.                        |
| **Third Party** | An independent software vendor, platform, or other organisation that sends messages for a SIDO through a PA. The SIDO keeps the rights to the Sender ID; the Third Party does not become its owner. |

If a Third Party manages SMS for you, select that organisation as the Third Party and Phonovation as the OPA in the registry. If you integrate directly with the Phonovation API, you normally do not need to select a separate Third Party.

<CardGroup cols={3}>
  <Card title="ComReg Sender ID Registry" icon="building-columns" href="https://www.comreg.ie/industry/electronic-communications/nuisance-communications/sms-sender-id-registry/" cta="Read the requirements" arrow="true">
    Review ComReg's current registration requirements and service updates.
  </Card>

  <Card title="Register or sign in" icon="user-check" href="https://senderid.comreg.ie/" cta="Open the registry portal" arrow="true">
    Register your organisation and Sender IDs, or manage existing registrations.
  </Card>

  <Card title="Registry guide and Q&A" icon="circle-question" href="https://www.comreg.ie/industry/electronic-communications/nuisance-communications/sms-sender-id-registry/registry-qa/" cta="Read ComReg's guidance" arrow="true">
    Find official explanations for SIDOs, OPAs, Third Parties, activation, and Sender ID rules.
  </Card>
</CardGroup>

## Register for Irish delivery

Use the [ComReg Sender ID Registry portal](https://senderid.comreg.ie/) to register your organisation and Sender ID. ComReg also publishes a [registry guide and Q\&A](https://www.comreg.ie/industry/electronic-communications/nuisance-communications/sms-sender-id-registry/registry-qa/).

<Steps>
  <Step title="Register your organisation as the SIDO">
    Create or sign in to your registry account and register the legal organisation that owns the Sender ID. If you use a Third Party, your organisation still remains the SIDO.
  </Step>

  <Step title="Register the Sender ID">
    Search for the Sender ID first. If it is not registered to your organisation, submit a request and complete ComReg's verification process.
  </Step>

  <Step title="Select Phonovation as the OPA">
    Authorise **Phonovation** as the Originating Participating Aggregator for the Sender ID. Add the correct Third Party as well if another platform or software vendor manages your messages.
  </Step>

  <Step title="Tell Phonovation Support">
    Email [support@phonovation.com](mailto:support@phonovation.com) with the exact Sender ID and the Phonovation account it should be assigned to. Selecting the OPA in ComReg does not automatically assign the Sender ID to your Phonovation account.
  </Step>

  <Step title="Wait for account assignment">
    Registry permission usually reaches Phonovation in about one day, but it can take longer. Phonovation will assign the Sender ID to your account after the permission is available.
  </Step>

  <Step title="Use it in the API">
    After Phonovation confirms the assignment, place the Sender ID in the campaign request's `from` field. Do not use it for production traffic before confirmation.
  </Step>
</Steps>

## Already registered with ComReg?

Registration alone is not enough. Sign in to the registry, open **My Sender IDs**, and confirm that Phonovation is authorised as the OPA for every Sender ID you intend to use through this API.

After adding Phonovation, email [support@phonovation.com](mailto:support@phonovation.com). Permission is normally available to Phonovation in about one day; once received, the team will assign the Sender ID to your account.

## Sender ID limits

The campaign API and the ComReg registry apply related but separate rules:

| Sender ID type               | Limits                                                                                                                                                                                                                 |
| ---------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Irish alphanumeric Sender ID | ComReg normally requires 3–11 characters. It must identify the organisation and cannot be generic. Permitted characters may include letters, numbers, spaces, hyphens, and commas, with no leading or trailing spaces. |
| Numeric Sender ID            | The API accepts up to 20 digits. Values from `50000` through `59999` are reserved and cannot be used.                                                                                                                  |
| Other API value              | The API permits up to 11 characters, but destination-country, network, account, and registry rules still apply.                                                                                                        |

ComReg treats registered Sender IDs as case-insensitive. The registry preserves the registered casing, but another casing of the same value cannot be registered as a separate Sender ID.

Leading and trailing spaces are removed by the campaign API. A Sender ID must contain at least one visible character and must be active on your account. For Irish recipients, a recipient whose Sender ID is not permitted may be skipped while other valid recipients continue processing.

## Dedicated longcodes

A dedicated longcode is a mobile number used as the Sender ID. It can receive replies and incoming SMS, enabling two-way messaging. A normal mobile longcode is separate from the ComReg alphanumeric Sender ID registration process.

Longcodes must be purchased and provisioned on your account. Contact [sales@phonovation.com](mailto:sales@phonovation.com) to discuss availability, pricing, and inbound-message requirements. After provisioning, use the longcode in the campaign request's `from` field.

## International Sender IDs

Sender ID rules differ by country and mobile network. A value accepted in Ireland may require local registration, pre-approval, or a different Sender ID type elsewhere; it may also be rewritten or rejected.

Before sending internationally, contact [support@phonovation.com](mailto:support@phonovation.com). The team can help you work through the requirements for the destination countries and confirm what must be enabled on your account.

<Card title="Create campaign reference" icon="paper-plane" href="/phonovation-api/api-reference/campaigns/create-campaign">
  Review the exact `from` constraints in the request schema.
</Card>