I strongly recommend keeping merchant account and gateway separate. The average business will change credit card processors every two years, usually seeking to reduce costs. Most will rarely change their gateway, because it works, and is not a big factor in cost. With a separate gateway, disruption is minimized when changing processors.

Gateway Vendor Selection Tips:

Where will you accept cards? Is it all via shopping cart? If other methods, how easy is it for accounting to reconcile and research transactions from multiple sources? Does the gateway support all the methods you need?

How long are records available for research? Ask accounting about how long they like to have data and consider audit needs.

Are you business to business? Qualified companies will want a gateway that supports level 3 data, with interchange, the bulk of credit card processing fees, rate savings sometimes exceeding 1%.

Do you have customers that want to keep cards on file? Will the gateway support all your needs to maintain PCI Compliance and keep employees from ever having access to full card data.

How will the gateway help manage interchange?

How will the gateway help reduce merchant PCI Compliance burden?