http://developer.authorize.net/api/simplecheckout/

How Simple Checkout Works

To generate the buttons, you simply enter applicable information such as an item description and price into the Authorize.Net Merchant Interface. HTML code is then generated automatically, which you can copy and paste into your Web site. When customers click your Simple Checkout button, they are taken to our secure, hosted payment form to enter their payment information, along with any other required information.

Because sensitive card data is collected using our secure servers, Simple Checkout can help simplify your compliance with the Payment Card Industry (PCI) Data Security Standard.

In short, with authorize.net's "Simple Checkout" no CC data is processed by the store itself. PCI compliance is NOT required.

Server Integration Method (SIM)

SIM provides a customizable, secure hosted payment form to make integration easy for Web merchants that do not have an SSL certificate.

In short, with authorize.net's "Server Integration Method" no CC data is processed by the store itself. PCI compliance is NOT required.

Advanced Integration Method (AIM)

AIM is Authorize.Net's recommended connection method and offers the most secure and flexible integration for all types of transactions, including mobile, websites and other business applications.

AIM allows merchants to host their own secure payment form on a website, mobile device, etc., and send transactions to the payment gateway using an end-to-end secure sockets layer (SSL) connection.

In short, with authorize.net's "Advance Integration Method" the CC data IS processed by the store. PCI compliance IS required.

Cheers
RodG

RodG:

PayPal is also a credit card processing Gateway, but since the CC details are never processed by the store itself (using IPN or Express checkout) then PCI compliance is NOT required for the store itself.

I've never used Authorize.net, but if "It's all done on Authorize.net's website." as stated by aperfecthost, then PCI compliance is not required for the store here either.

Cheers
RodG

Authorize.net does indeed require PCI compliance.. Had to do the whole certification exercise with my clients who use Authorize.net.. The regular PayPal service (AKA PayPal Express or PayPal IPN) is not a TRUE payment gateway.. it is a 3rd party payment processor.. You are in fact using PayPal's merchant account and gateway to process credit cards.. the entire processing happens on PayPal's site.. which is why PCI compliance is not required for a standard PayPal account.. Payments Pro requires a merchant account, but payments are processed via PayPal's gateway, PayFlow is the equivalent to Authorize.net.. It is PayPal's own gateway.. PayFlow works MOST like Authorize.net..

A third-party processor such as PayPal lets you accept online payments without a merchant account of your own. Instead, they let you use their merchant account under their own terms of service, usually with very little setup required.

http://developer.authorize.net/api/compare/

Store PCI Compliance is only needed with the Advanced Integration method.
SSL (and therefore PCI) is NOT needed for the other three methods.

Compare E-Commerce APIs

Choose one of the integration methods below to connect a Web site to the payment gateway for processing transactions. Also view the Merchant Integration Guide, which focuses on the settings available in the Merchant Interface for configuring a Web site connection to the payment gateway.

RodG:

http://developer.authorize.net/api/simplecheckout/

How Simple Checkout Works

To generate the buttons, you simply enter applicable information such as an item description and price into the Authorize.Net Merchant Interface. HTML code is then generated automatically, which you can copy and paste into your Web site. When customers click your Simple Checkout button, they are taken to our secure, hosted payment form to enter their payment information, along with any other required information.

Because sensitive card data is collected using our secure servers, Simple Checkout can help simplify your compliance with the Payment Card Industry (PCI) Data Security Standard.

---

In short, with authorize.net's "Simple Checkout" no CC data is processed by the store itself. PCI compliance is NOT required.

Server Integration Method (SIM)

SIM provides a customizable, secure hosted payment form to make integration easy for Web merchants that do not have an SSL certificate.

In short, with authorize.net's "Server Integration Method" no CC data is processed by the store itself. PCI compliance is NOT required.

Advanced Integration Method (AIM)

AIM is Authorize.Net's recommended connection method and offers the most secure and flexible integration for all types of transactions, including mobile, websites and other business applications.

AIM allows merchants to host their own secure payment form on a website, mobile device, etc., and send transactions to the payment gateway using an end-to-end secure sockets layer (SSL) connection.

In short, with authorize.net's "Advance Integration Method" the CC data IS processed by the store. PCI compliance IS required.

Cheers
RodG
Right.. and MOST folks using Authorize.net are doing so using AIM, not SIM..

PS. The DPM method is misleading (wrong). PCI (and SSL) will be required, because although the data is stored on Authorize.net the CC data is still processed by the store.

Sheesh.... Even they don't seem to know the rules. What chance do the rest of us have? :)

Cheers
RodG