Amy asks;

I've been trying to find out if it is necessary to have a customer create an account in order to purchase through the shopping cart.

With standard osCommerce, the answer is "yes, an account needs to be created". However, it is simple to wrap this up as part of the checkout procedure by not mentioning the word "account". You can remove all references of "account" in the language files – call it "profile" or somesuch instead.

In the actual checkout procedure, remove the need for the buyer to insert passwords, and instead have a checkbox saying "remember my details". If they check the box, then send a random password by email. Streamline the checkout process by removing the "create account success" page.

So, to sum up;

Yes, an account is needed. But it is easy to make it LOOK LIKE an account is not needed.

Other Options

Of course, there are a number of contributions that address this, and they are all rubbish and pointless. I know of one that is called "Fast Easy Checkout", which is a complete dogs dinner of code. Avoid them all, and just streamline the usual osCommerce checkout process would be my advice.