CartaSi is an Italian payment processing service that primarily issues CartaSi branded VISA and MasterCard prepaid, debit and credit cards. This is in addition to its online and mobile payment systems. While the company primarily serves in Italy, its partnerships with global payment systems like VISA and MasterCard give its cards a global scope of operation.
It is safe to assume that all reputable online casinos accept either VISA or MasterCard (usually both). This means that CartaSi cards are accepted by almost all reliable web-based casinos. They also have a stellar security record.
One usually links their card to their bank accounts to facilitate loading.