Bundle ID / Package name properly formatted

Bundle ID (iOS) and package name (Android) are the permanent, immutable identifiers that link every version of your app, every review, every user install, and every in-app purchase receipt to a single entity in the store databases. A malformed identifier — one that uses uppercase characters, hyphens, or has fewer than three segments — causes binary submission rejection before review begins. Using a generic placeholder like com.example.app in production is grounds for immediate rejection. Critically, once an app is published, changing the bundle ID or package name creates a brand-new app listing, breaking updates for all existing users. The Apple Bundle ID spec (apple-bundle-id) and Android Application ID spec (android-application-id) both mandate strict reverse domain notation.

Set both identifiers in app.json before first submission. Use strict reverse domain notation: all lowercase, alphanumeric segments only, each segment starting with a letter, minimum three segments.

// app.json
{
  "expo": {
    "ios": {
      "bundleIdentifier": "com.yourcompany.appname"
    },
    "android": {
      "package": "com.yourcompany.appname"
    }
  }
}

Choose this identifier before first TestFlight or Play Console submission — it cannot be changed without losing all existing installs and reviews. Avoid hyphens in any segment (they are illegal in both specs). Segments must not start with a digit.

• ID: mobile-store-readiness.build-config.bundle-id-format
• Severity: critical
• What to look for: Check app.json for ios.bundleIdentifier (iOS) and android.package (Android). Count the dot-separated segments in each identifier. Format should be reverse domain notation: com.company.appname (e.g., com.example.myapp). Package names should not contain numbers at the start of any segment, should be lowercase, and use only alphanumeric characters and dots.
• Pass criteria: Both bundleIdentifier (iOS) and package (Android) follow reverse domain notation: com.company.appname format, lowercase, valid characters only. Each identifier must have at least 3 dot-separated segments. Before evaluating, extract and quote the exact bundleIdentifier and package values found in app.json or build config.
• Fail criteria: Bundle ID or package name is missing, uses invalid characters (hyphens, underscores in the package name segment, uppercase letters), contains numbers at segment start (e.g., com.2company.app), has fewer than 3 segments, or uses a generic name like com.example.app in production.
• Skip (N/A) when: Project targets only iOS or only Android, so one of the identifiers is N/A.
• Detail on fail: Specify the issue. Example: "Android package 'com.MyCompany.myapp' uses uppercase — must be lowercase: 'com.mycompany.myapp'" or "iOS bundleIdentifier missing from app.json"
• Remediation: Bundle ID and package name uniquely identify your app in app stores. Follow the reverse domain notation format:
  1. In Expo app.json:

     "ios": { "bundleIdentifier": "com.yourcompany.appname" },
     "android": { "package": "com.yourcompany.appname" }
     

  2. Rules:
     • Use reverse domain: com.yourcompany.appname
     • All lowercase
     • Alphanumeric and dots only (no hyphens or underscores)
     • Each segment must start with a letter, not a number
     • Must be unique — this ID locks your app to this identifier permanently
  3. Once released, never change the bundle ID/package name — it's permanent for app updates