I get a market ban every time I add funds with my card O_o??

I used to get that when adding funds with an unverified card, but it stopped after a while when it was confirmed as mine, pretty much. Shows up on my account details. Does yours?

I knew somebody who had issues because he used his card on more than one account (or at least that was what he believed was causing the issues). If you have ever used the card on an alt account or a family members account that might be the problem. If not then just ignore me...

I had my visa card verified for years. And then one day a few months ago I was lazy and just added some funds via paypal. Since then I've had the same problem and my card was therefore 'unverified'. Well, no error for me, but the transaction test where it should show whatever amount never showed up on my bank acc, so I just gave up after a couple of tries.

Now I just add funds from my paypal everytime and therefore no market ban! :)

Not really sure if there's any way other than topping up the account in advance with some spare money, and remember to not spend it until next time you would've pulled out the CC... certainly that's what I did (the topping up part. The not spending bit is a bit too difficult for me to follow through on!)

It basically detects 'unusual patterns in the frequency of you adding funds' and thus forces you to go through an extra ban because you're showing 'suspicious behaviour'. The only way to avoid it is to add funds habitually in a way that the system perceives as 'natural'. Obviously, this is much easier said than done, and so the only real solution is to keep funds available and well in advance so you will never be caught empty-handed. Which again benefits Steam in the end since you will waste some money keeping this stream going.