We do hosing services. Our clients have their own merchant number issued by different acquiring bank or merchant service companies.
Can we license payment gateway software or buy a white label payment gateway software to do the payment gateway services without acquiring bank partnership?
(Helping our clients to transmit the transactions to processor with their own merchant number. No funding, no merchant number issuing. Something like old business style of authorize.net before they start issuing merchant number)
You can license payment gateway software and provide gateway services without partnering with an acquiring bank.
An acquiring partnership is necessary when you want to become an ISO or a payment facilitator (PayFac).
If you want to be just a payment gateway provider, acquiring partnership is not required.
The important thing you should understand is as follows. Even when you purchase some white-label or hosted solution, in order to support merchant accounts serviced by some processor, you still need to go through certification with this particular processor. For example, if you want to support merchant accounts of First Data, TSys, and Elavon, you will need to either partner with a white-label gateway that already has respective certifications or certify your own dedicated gateway instance with the listed processors.
So, you do not need an acquirer to issue a merchant account to you, but you do need to go through certification with processors that are going to issue merchant accounts to your clients.