The thing with redeemable codes is that parties need to trust each other. You can't use escrow because there's no good way to verify the validity of the card securely so one would have to go first and the other should trust them for not getting away without delivering.
So that's all ? beside that , It's impossible to get them chargebacked if both parties basically trust each other to make the transaction .
I remember that Ukash stated explicitly in their terms that they do not allow Bitcoin related transactions. Ukash is now paysafecard though and their terms don't say anything about bitcoin. But yeah, if you trust the other party you're good. I've even sites that allow you to buy using paysafecards. Bitboat.com does IIRC.
I see , well thanks for your answer , I thought they are both reversible and that's why I didn't use them on the first place .
even if I don 't understand how Ukash will know if the transaction made is related to bitcoin or not , and what if it's the case ?
Ukash is now paysafecard. AFAIK paysafecard doesn't care about bitcoin transactions so it should not be a problem. Paysafe might not perfectly irreversible, although details are unclear. But at the very least we know that there are some bitcoin exchanges using them so it can't be that bad.
It make more sense I suppose , thanks !
for what comes to the exchanges , I only know Virwox.com and they don't let you enter they voucher , they will require an account on the Paysafecard otherwise you won't be able to redeem anything . not biggy though
ty again 
