There are tons of Merchant Account Providers (MAPs) on the Internet. They come in all shapes, sizes and flavors. It would be best to do some good research about this subject as it will probably end up saving you quite a bit of money in the long run. If you need additional information about the generalities of merchant accounts, please check the following sites:

Establishing a Merchant Account at Your Web Site www.workz.com

Purchasing over the Internet www.firstdata.com

Unraveling the Mysteries of Merchant Credit Card Accounts for Web Commerce www.wilsonweb.com

How to get your own Merchant Accounts cheap! www.marketingtips.com

Merchant Account

Merchant account processing services are provided by a bank or a third-party processor to the merchant. These services include authorization of credit cards, settlement of funds through the bankcard associations (MasterCard/Visa), depositing of funds to checking accounts, merchant billing, and account activity reporting.

Payment Gateway

This is a software/service provided by a third party that interfaces over the financial networks to settle transactions between your merchant bank and your customer's bank.

Service Provider

This is a software/service interface to the Payment Gateway. It is used to securely collect credit card information from your customer, maintain order logs, configure a transaction with the Payment Gateway, and interpret gateway responses in a user friendly format for your customer.

For further information on definitions check here:

On the purchase order, you request that the shopper send you their credit card information separately either by mail, fax, or telephone. You will need a Merchant Account and preferably a toll free telephone number.

You return an encrypted credit card information form to the shopper after they submit the purchase order. This information is saved to an order log for subsequent manual processing by you. You will need a Merchant Account and a Service Provider Utility for capturing and saving the credit card information.

You return an encrypted credit card information form to the shopper after they submit the purchase order. This information gets processed over the financial networks while the shopper is still at your store.

You will need a Merchant Account and a Service Provider Utility for capturing and saving the information and configuring a request to a Payment Gateway account. You will need the gateway account for connecting to the financial networks.

Other than the list provided, here is a list of merchant service providers from Merchantworkz that may be worth investigating: