Recently deleted
In some Android phones, deleted contacts can be retrieved by recent deletion. Take Huawei P30 as an example. We can go directly to Settings-Organize Contacts-Recently Deleted through the Contacts application, and retrieve the deleted contacts directly through this folder. Long press the contact person who needs to be restored to directly select Restore.
Import SIM card address book
In Apple's mobile phone, the contact information will not be directly displayed in the address book after the SIM card is inserted, so if the phone number is deleted, you can try to import the SIM card address book again, and if the SIM card has the contact information of the other party, you can directly achieve the purpose of recovery. This operation can be done by directly importing the address book of the SIM card into the settings of Apple's mobile phone.
Cloud backup
In addition to the above two simple methods can be used to recover the phone number, if the phone number in the mobile phone has been backed up before, you may wish to retrieve the deleted contact directly by backing up the content. Take Apple's mobile phone as an example, you can log in to iCloud official website directly according to your account password to check the backup in the address book, and you can recover it directly if you find the other party.