If you’ve had your credit card stolen or discover that you’ve lost it, you should report it missing straight away as it could affect where you stand legally if the card is subsequently used by a thief.
Your card provider should always refund you in full for any transactions that take place after you've reported your card missing.
If you don't realise for a number of days that your card has been lost or stolen, you should still be able to get your money back.
Although, you could be liable for the first £50 of any sum spent on your credit card before you reported it stolen.
In practice, many banks waive this £50 contribution so it's worth checking the terms and conditions or checking with your provider to see if you have to pay.
If your credit card provider thinks you're responsible for the transaction or that you've authorised someone else to buy the item using your card, then it needs to prove this - you don't need to prove you weren't responsible.
If you were responsible for the transaction or authorised someone else to use your card, your card provide won't refund you anything.
Most banks will refund you in full any money that has been fraudulently taken from your card. You must report it missing immediately as this could affect your legal position if it's subsequently used fraudulently. However, if your card provider can show that you've been grossly negligent, it can refuse to refund you anything.
If your debit card provider can show you've failed to take reasonable measures to keep your debit card and/ or card details (including your PIN) safe, then it could make you responsible for the first £50 of any disputed transaction.
If your card provider can demonstrate that the disputed transaction was a result of you acting fraudulently or with gross negligence, then it can refuse to refund you.
If your card provider thinks you've failed to take care of your card or bank details - or worse, that you've been fraudulent or grossly negligent - then it's for them to prove this.