Yes. As part of the cardholder agreement, you need to report fraudulent or incorrect transactions as soon as you see them.
For most types of disputes or fraud cases, you have up to 90 days from the transaction date to report the issue to KOHO.
Are there any exceptions to the 90-day dispute window?
In some cases, yes. For example, if you bought tickets or prepaid for a service months in advance, you may still be able to dispute the charge as long as the event or service was scheduled within the last 90 days, even if the original purchase was made earlier.