Ask HN: How can one overcome the hurdle of getting merchants onboard?

We have built an auto repair platform which lets car owners stay informed about their cars scheduled maintenance and other repairs. Car owners can post repair request, receive quotes from local mechanics, and book appointments.

We have been successful getting local mechanics to sign up. Currently, we have a mix of local as well as franchise repair shop owners. However, they have been reluctant in providing financial information which would be essential in order to disburse payments to their account (we are using Braintree Payments).

What are some options or approaches that could help to get them over this barrier?

Thanks in advance.