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

# Register a Package Name for Your Rey App

> Choose a unique Android package name (application ID) for your Rey app so Google Play can identify it across the Play Console, signing, and services like Firebase.

Every Android app needs a unique **package name** — a reverse-DNS string like `com.reylabs.myapp` — that Google Play uses to identify your app across the Play Console, app signing, and services like Firebase and Google Sign-In. Android calls this the **application ID**; it's the direct equivalent of an iOS Bundle ID.

You choose the package name **once** and configure it in Rey. Unlike Apple, Google doesn't require you to pre-register the identifier in a separate portal — it's claimed the first time you create the app record in the Play Console.

## Prerequisites

* An active [Google Play Developer account](/publishing/app-stores/play-store/google-play-developer-account).
* A chosen package name string (see naming rules below).

## Choose a package name

Package names follow **reverse-DNS notation** and must be globally unique across all of Google Play.

<AccordionGroup>
  <Accordion title="Format and rules">
    * Lowercase letters, numbers, and dots. Underscores are allowed inside segments but hyphens are not.
    * Reverse-DNS style: start with your domain in reverse, then the app name. Example: `com.reylabs.taskflow`.
    * At least two segments (e.g. `com.taskflow` is the minimum, `com.reylabs.taskflow` is recommended).
    * Each segment must start with a letter.
    * Must be unique across all of Google Play — you cannot reuse one another developer has claimed.
    * **Cannot be changed** after your app is published to Google Play, so pick carefully.
  </Accordion>

  <Accordion title="Good examples">
    * `com.acme.notes`
    * `io.reyapp.taskflow`
    * `com.yourcompany.yourapp`
  </Accordion>

  <Accordion title="Bad examples">
    * `MyApp` — not reverse-DNS.
    * `com.google.myapp` — you cannot use Google's namespace.
    * `com.acme.notes.v2` — don't include version numbers.
    * `com.acme-labs.notes` — hyphens aren't allowed.
  </Accordion>
</AccordionGroup>

<Warning>
  Choose your package name carefully. It cannot be changed once your app is published to Google Play, and it must match the identifier you configure in Rey.
</Warning>

## Reserve your package name in the Play Console

Google claims the package name when you create the app record. If you want to lock it in before finalizing the rest of your listing, walk through app creation now with your chosen package name.

<Steps>
  <Step title="Sign in to the Play Console">
    Go to [play.google.com/console](https://play.google.com/console) and sign in with the Google account tied to your developer account.
  </Step>

  <Step title="Start creating an app">
    Click **Create app** in the top right of the Play Console home page.
  </Step>

  <Step title="Enter your package name context">
    Fill in an app name, default language, and app/game type. The package name itself is set when you upload your first build, but the app record reserves the slot in your account.
  </Step>

  <Step title="Save the draft">
    Click **Create app**. The Play Console saves a draft app record you'll come back to in the next guide.
  </Step>
</Steps>

<Tip>
  If you'd rather choose the package name later, skip this section and continue to [Register your first app](/publishing/app-stores/play-store/register-first-app) — you'll set it there.
</Tip>

## Add the package name to Rey

<Steps>
  <Step title="Open Publish settings in Rey">
    In the Rey editor, click **Publish** in the toolbar and select **Google Play** as the target.
  </Step>

  <Step title="Paste your package name">
    In the **Android settings** section, paste the exact package name you plan to use (e.g. `com.reylabs.taskflow`).
  </Step>

  <Step title="Save">
    Rey uses this package name when it signs and submits your Android build. It must match the identifier registered in the Play Console exactly — typos will cause the submission to fail.
  </Step>
</Steps>

## Next steps

* [Register your first app in the Play Console](/publishing/app-stores/play-store/register-first-app) using the package name you just chose.
* Return to the [Publish to Play Store overview](/publishing/app-stores/play-store/overview) for the full submission walkthrough.