Every bank makes it's own decisions on credit policy and what the minimum income/net worth you must have. However, the associations do say what the minimum credit line can be associated with a card. So you must qualify for a different minimum w/ a World or Signature than with a Classic or a Gold card. But how this minimum is assigned depends on the issuer.

As for the benefits. Both World and Signature offer no pre-set spending limit. This means that you have a defined credit limit within which you are allowed to revolve. For example, you have a credit limit of $5,000 and can also spend/revolve up to this amount. However in a certain month you might spend $6,000. With a nonWorld/Signature card you would have to pay an over the limit fee, with these cards you just have to pay the full $1000 over your limit and any standard minimum payment when your monthly statement is issued. The amount that the issuer allows you spend over your limit is adjusted regularly and based on your income, spending and payment habits.

As for the differences between Signature (Visa) and World (MasterCard)... They tend to be minor.

Hope this helps answer some of the questions.

------------------
I Love New York -- Viva Espaņa