[vladvasiliu]

The merchant can choose wether and when to use 3dsecure (at least in France). I work for a company that uses Paybox for online payments. We can set an amount above which 3dsecure is used, e.g 20 EUR. I'm guessing the bank has to support 3dsecure, but they can't or at least don't impose it.

[mack73]

I work with fraud detection at an online travel agency. If you use 3D Secure and there is a fraud, your insurance will cover the cost of that transaction. As a merchant you may bypass (not use) that security feature at your discression. 3D Secure is a Mastercard feature, no?

[vladvasiliu]

3dsecure works with Visa too. I don't know about AmEx, although I do know that for Point Of Sale payments we have to have a special bank contract (one for Visa / Mastercard and one for AmEx).

I suppose the merchant decides wether to use this or not by trying to find a balance between user experience and fraud risk.

In our case I think the limit is set right above the usual purchase amount (we sell movie tickets). It's low enough that a fraud wouldn't hurt us too badly and there's not much incentive for it either. Also, most of the clients don't have to fiddle with 3dsecure (in my case I would have to cary a fob around, which I never do), so it's a better experience for them.

If someone tries to buy a lot of tickets at once, they are more likely to be doing something fishy so we use 3dsecure.