# Is bundle ID really needed?

**URL:** <https://discuss.appium.io/t/is-bundle-id-really-needed/19288>\
**Category:** Support\
**Created:** [October 23, 2017, 7:44pm UTC](https://discuss.appium.io/t/is-bundle-id-really-needed/19288 "2017-10-23T19:44:38Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![4jp.hennessey](https://discuss.appium.io/letter_avatar_proxy/v4/letter/4/7ea924/32.png) [@4jp.hennessey](https://discuss.appium.io/u/4jp.hennessey)\
**Post date:** [October 23, 2017, 7:44pm UTC](https://discuss.appium.io/t/is-bundle-id-really-needed/19288/1 "2017-10-23T19:44:38Z")

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I have been exploring Appium with Java by itself, as well as for a proof of concept with Serenity. In neither case did I specify the bundleId value in my capacities, yet my sample tests run fine on my iPhone 6 simulator and my physical Android device. Can someone please explain under what circumstances it’s a necessity?

Note that my app is from React Native in case that makes a difference.

Thanks in advance!

- Platform (iOS)
- Appium version = 1.7.1
- Simulator
- Client langauage = Java
- OS = MacOS

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**Author:** ![wreed](https://discuss.appium.io/letter_avatar_proxy/v4/letter/w/919ad9/32.png) [@wreed](https://discuss.appium.io/u/wreed)\
**Post date:** [October 23, 2017, 8:38pm UTC](https://discuss.appium.io/t/is-bundle-id-really-needed/19288/2 "2017-10-23T20:38:13Z")

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> [@4jp.hennessey](#):
>
> iPhone 6 simulator

“Bundle ID of the app under test. Useful for starting an app on a **real device** or for using other caps which require the bundle ID during test startup. To run a test on a real device using the bundle ID, you may omit the 'app’ capability, but you must provide 'udid’.”

[https://appium.io/slate/en/master/?java#ios-only](https://appium.io/slate/en/master/?java#ios-only)