Apple's new smartphones, the iPhone 7 and the iPhone 7 Plus, have started to reach customers and the new smartphones are one of hottest devices in the market. Older iPhones are also in good demand in the market and many existing iPhone owners may either sell their older model or exchange it for a newer one.

Selling an old iPhone or iPad can generate cash that can go toward the purchase of the latest model. However, incidences of identity theft and financial crime via smartphones are increasing and iDevice owners should take adequate steps to ensure they wipe out their details from their iOS device before exchanging it or selling it.

Apple also recommends that current iPhone and iPad owners delete personal information before selling or giving away their handset. However, iPhone users should not manually delete contacts, photo streams, documents and more.

"This would delete your content from the iCloud servers and any of your devices signed in to iCloud," says Apple. "On your device with iOS 10, make sure that you sign out of iCloud before you erase your device."

Here is how to effectively wipe out data from an iPhone or an iPad.

1) Customers who have an iPhone and Apple Watch should unpair their devices.

2) iPhone and iPad owners should back up their iOS device so that they retain important information.

3) iDevice owners should tap on Settings > iCloud and then tap on Sign Out. In case the iPhone is running iOS 7 or older iOS versions, users will have to tap Delete Account.

4) Tap Sign Out again and then tap on Delete from My iPhone and enter the password.

5) Go to Settings and then tap General > Reset > Erase All Content and Settings. In case Find My Phone is turned on, a user will have to enter their Apple ID and password.

6) The iDevice may ask the user for Restrictions passcode or device passcode. Owners will have to enter the required passcode and then tap Erase.

If the above steps were not taken before selling or handing over the device, then customers should follow the following steps:

1) Request the new owner to delete old information by following the above steps.

2) Customers can sign in to their Find My Phone or iCloud account from another device, then select their old iPhone and click on Erase. After erasing the old iPhone, users should also tap on Remove from Account.

3) If the above step is not possible then customers should change their Apple ID password. This step will not delete personal information from the old phone but it will refrain the new user from deleting information from the original owner's iCloud.

4) In case a customer is moving away from iPhones then they should de-register iMessage.

5) iPhone and iPad users who access Apple Pay can also remove debit or credit card details from iCloud. Select Settings to check the devices that use Apple Pay and then tap the device and click Remove.