What happens if your phone is stolen?
Nothing, for payments, while the phone stays locked, because it will not pay without checking who is holding it. That is the substantive advantage over a card, which anyone who finds it can tap. What matters afterwards is the account rather than the plastic.
A locked phone does not pay
Presenting a payment credential requires the phone to be satisfied that its owner is present, through unlocking or a biometric check.
A thief holding a locked phone therefore cannot tap it against a terminal and have anything happen, which is not true of the card in the same pocket.
This is the single most useful thing to know at the moment of a theft, because it removes the most immediate fear and lets you deal with the rest in order.
The case that is different
A phone taken while unlocked, or taken along with the means of unlocking it, is a different situation and a considerably worse one.
The payment question is then the least of it. Someone holding an unlocked phone has your messages, your mail, and the resets those permit.
That is why the order of actions below starts with the account rather than with the cards: the account is the thing that unlocks everything else.
What to do, in order
Lock the device remotely through your platform account, from any browser, which is the single action that does the most.
Change the password of the account the phone is signed in to, since that account is the route to everything else.
Then suspend the payment credentials, which the bank or the platform can do without your having the device.
Then report the theft, and only then worry about the physical card, which is unaffected unless it was in the same pocket.
What happens afterwards
A payment credential on a lost device can be suspended without cancelling the underlying card, which is one of the quiet advantages of the arrangement.
A replacement device is provisioned afresh rather than restored, so nothing is transferred that should not be.
Exactly which of these steps the bank performs and which the platform performs varies by issuer and by country, and the issuer's own instructions are the authority.
And read the statements for a while afterwards, which catches whatever the sequence above missed.
Frequently asked questions
Can a thief pay with my locked phone?
No. It will not present a payment credential without checking that its owner is present.
What if it was unlocked when taken?
Then payments are the smallest problem. Lock the device remotely and change the account password first.
Do I have to cancel my card?
Not necessarily. A device credential can usually be suspended without cancelling the underlying card.
What is the first thing to do?
Lock the device remotely through your platform account. It is one action and it does the most.