Banks are issuing warnings to their customers who are using Apple Pay - Do not store other people's fingerprints on your iPhones. This warning comes as the use of Apple's Touch ID and Apple Pay is becoming more popular each day.

Some of the banks' warning or terms which address this issue states that if a person consents to another person using their smartphones and allowing them to register their fingerprints in it, that person is considered to be the same as someone who has failed to keep their card and security details safe.

One can only deduce that by this warning, the banks can decline to help on cases where customers claim to be victims of fraud or refuse refunds for disputed transactions. Touch ID is Apple's system where one is able to store encrypted fingerprints which can be used to unlock smartphones. It is also the way to authorize an Apple Pay payment. Each Touch ID scanner is built at the base of an iPhone's screen.

Meanwhile Apple Pay is Apple's mobile payment service which enables consumers to make payments online or in-store using only their iPhones and iPads with a fingerprint sensor. American Express card users can also use Apple Pay in checkout of retailers' application on their iPhones or iPads.

This service enables a very effective method of checkout where the consumer's credit data will be kept safe by using a tokenization technology. This tactic generates a specific code for the credit card which can only be used with Apple Pay.

For in-store consumers, when their iPhone is near a payment point, the consumer's bank card that has been set up in Apple's electronic wallet will be seen to flash up on the screen. The consumer will then authorize the payment by putting his or her registered finger in the scanner of the phone.

This takes only less a minute or a couple of seconds only and is secure because of the fingerprint scanning and verifying. Apple Pay has been launched and made available in the US since October 2014 and has been recently extended to the UK this July.