Your smartphone can hold a lot of data, but its storage space isn't unlimited. Removing unnecessary or out-of-date contact data from your device is one way to free up a little room for other content. Whether you're using an Android device or an iPhone, you can delete old or duplicate phone numbers directly in your phone's dedicated contacts app.
Delete From Android Devices
Tap the "Contacts" app icon on the home screen of your Android device to launch the Contacts app. On standard Android devices, the Contacts icon is orange and has an image of a person superimposed on it.
Scroll through your contacts to locate the contact you want to delete. If you have a large number of contacts, tap the "Search" field at the top of the Contacts directory and enter the contact's name to display a list of matches.
Press and hold the contact you want to delete. Your Android device will switch to bulk contacts management mode at this point, displaying check boxes next to all of your contacts.
Place check marks beside all of the contact entries you want to remove and then tap the "Trash" icon in the top right corner of your screen. The Trash icon resembles a garbage can. When you tap the "Trash" icon, the Delete Contact prompt appears.
Tap "OK" on the Delete Contact prompt to confirm that you want to delete the selected contacts.
Delete From iPhone
Tap the "Phone" icon on the home screen of your iPhone device to launch the Phone app. Tap the "Contacts" icon at the bottom of the screen to load a list of contacts on your device.
Alternatively, you can access the Contacts app directly by tapping the "Contacts" icon on the home screen.
Scroll through your contacts and tap the contact you want to delete. Contacts are listed alphabetically. When you tap a contact's name, that person's contact card appears.
Tap the "Edit" link in the top corner of the contact card, scroll down and tap "Delete Contact." Tap "Delete Contact" again to confirm that you want to remove the contact from your device.
If you want to delete only a contact’s phone number and not the entire contact, you can do so on both types of devices.
To delete a number from a contact on Android, launch the Contacts app, tap the name of the contact and then tap the “Edit” icon in the upper-right corner of your screen. The Edit icon resembles a pencil. Tap the phone number you want to delete and then tap the "-" icon located next to it. Tap the “Save” button at the top of your screen to save the contact with the phone number deleted.
On iOS devices, you can delete individual phone numbers from a contact via the Contacts app. Launch the Contacts app, tap the contact you want to edit, tap the “Edit” link in the top corner and then tap the "-" sign next to the phone number you want to delete. Tap “Done” to save your changes.
If you have a large number of duplicates on an Android device, the Merge Accounts feature can save you having to delete each duplicate entry manually. To use Merge Accounts, open the Contacts app, tap the “Menu” icon in the upper-right corner and tap “Merge accounts.”
A number of third-party apps have also been developed to help you merge and delete duplicate contacts. Visit the Google Play and iTunes stores to browse for contact management apps.
Information in this article applies to Android devices running Android 4.4 and to iPhones running iOS 7.1. It may vary slightly or significantly with other versions or products.