Can I integrate a Merchant ID Number with Authorize.net?

[MariOkudoduma]

I'm building an e-commerce website from scratch in Ruby on Rails. I currently have PayPal integrated into the site, but the client wants to go with a cheaper solution (that takes less cut than PayPal.) I don't have a website for them, they don't have integration docs. All I got was a Merchant Identification Number (MID). The guy from the payment company said that my client would be able to use this Merchant Identification Number when the shopping cart site asks for it.

The payment guy thinks that my client is using a pre-packaged solution like Volusion or Magneto.

Can I use the Authorize.net payment gateway with just a merchant identification number? It looks like from this page, http://activemerchant.rubyforge.org/classes/ActiveMerchant/Billing/AuthorizeNetGateway.html#method-M..., /omegle shagle /voojio that I need an Authorize.Net API Login ID and an Authorize.Net Transaction Key.

What information am I missing from the payment guy?

He said that we could use VeriSign or Authorize.net... but VeriSign was acquired by PayPal, wasn't it?

[Renaissance]

@MariOkudoduma, your client would need an authorize.net account. Your client would go through merchant services at his/her bank or would deal directly with authorize.net. Your client would get a login id and a transaction key with the account, and that is what you would use in your application. There is no way to run transactions on auth.net without API credentials. You can run test orders with sandbox credentials.