Taxes related to payment processing

Hi, I have a question regarding the laws concerning taxes and regulations regarding processing a payment. I am the administrator of a platform enabling two sides: the provider willing to provide and the client in need of a service. The provider can set a price for the service in which case we take a certain procentage as a commission for enabling this user to make money through our platform. In order to secure the client's payment for the duration of the transaction, that is until the transaction is verified to be complete by the receiver of the service the current payment solution imposes on us to take the whole payment into our account. To be exact about the issue we forced to accept the full payment for the service that is both the price set by the service provider and our commission for offering the service on our platform. Because my platform provides the service globally this puts us in a situation that in some countries we have to pay taxes for the money processed for the service provider.