>Do youthink it is possible to link directly to Visa and check the status of the payment as a merchant, or must we go through a third party validator?

I doubt that visa will even bother to talk to you.

As a merchant you must assume that a charge you entered for a sale you made went through as soon as you received a confirmation number (usually within seconds (or less) of entering the charge into the system).

As a merchant you also can make the above assumption UNTIL you receive a charge-back, which happens IF the customer refuses the charge.

If you have a signed receipt you can contest this and possibly win. Your chances of winning such a dispute decrease proportionally to the amount of verifiable data you have to show that the customer indeed received the goods or services from you.

Alex