I'm inquiring on a recent debit card scenario we've encountered in case anyone has some additional insights or feedback on how we can prevent a loss....

Customer indicates there are a number of charges on his account to a hotel that were not authorized. Customer stated he authorized a one-night stay for a business colleague, however the business colleague did not check out the next day; checked out a number of days later. The customer has been attempting to work this out with his colleague directly. (In the meantime, customer has received provisional credit). Customer attempted to resolve with the hotel as well with no luck.

Seems known that once you provide your card information for a hotel stay you authorize charges until checkout. What can we do to prove this? (Will a chargeback dispute provide us with this?)

Thoughts/suggestions on how to proceed here?

Doesn't sound like an unauthorized transfer to me.

1005.2(m) - 2. Authority. If a consumer furnishes an access device and grants authority to make transfers to a person (such as a family member or co-worker) who exceeds the authority given, the consumer is fully liable for the transfers unless the consumer has notified the financial institution that transfers by that person are no longer authorized.

I wondered if the definition applies in thise case. The customer gave the hotel his card information (over the phone I believe), not the colleague directly. (Though colleague benefited)

He authorized the charges for the hotel stay - the fact that his "colleague" stayed a couple of extra days or trashed the room or ordered room service - well he has to deal with his good friend for that.

Appreciate the help! When we notify the customer in writing regarding the denial of his claim, we refer to this definition in the regulation?

I would. It's cited as comment 2(m)-2 to Regulation E section 1005.2.

For whatever it's worth, I never recommend using a debit card at registration for accommodations or car rentals. Credit cards are much more protective of a consumer's rights.