There are dozens, or even hundreds, of sites that offer basic credit card generating programs, and discuss how you can use the fake numbers generated. Most of these (other than our own) don't work. Rather than recommending any particular one, we suggest that you search under "credit card generator" or "credit card verifier" in just about any search engine. You'll find lots of hits. (Be warned. Some of these are just come-ons that link you to legitimate credit card application sites.)
We are not in any way related to the following sites, except that we have confusingly similar names. As far as we know, these other sites offer perfectly legitimate services absolutely unrelated to us. Give them a try, and sorry for any confusion.