Ask HN: Accepting credit cards as an intermediary

We're a European startup working on an online service selling coworking or flexible office space. We accept a payment from the person booking the workplace, and pass the money on (minus our cut) to the owner of the workplace. As users are mostly (small) businesses, we want to also accept credit cards (we have other debit options already in place). Because we have no control over the workplaces/desks, our terms of service dictate that we are not liable for damages due to things like missing services.

When applying for credit card processing the processor however wasn't too happy to see that we don't carry the liability on the service being sold, only in being an intermediary.

The main question here being: does anybody have examples of sites that do charge a credit card, yet are just an intermediary. Or does anybody have tips/suggestions?