The American Express Premier Rewards Gold Card's credit limit actually varies from month to month. In other words, the card has no pre-set spending limit (NPSL). That doesn't mean Amex PRG offers unlimited spending. Rather, Amex may adjust your spending limit over time, based largely on your payment history. But they won't tell you when it changes, so you won't know exactly what your limit is most of the time.  

NPSL is a common feature among charge cards such as Amex Premier Rewards Gold. You also have to pay a charge card's balance in full every month to continue making purchases. But if you do so, and otherwise manage your finances responsibly, you may enjoy regular credit limit increases.

Here's what affects American Express Premier Rewards Gold Card credit limits:

• Payment history. Pay in full every month and you may get additional purchasing power. Late payments will have the opposite effect.
• Spending habits. Amex will look at your spending during previous months when determining what to give you for the current month. Try to not to spend beyond your means or drastically increase the amount you spend from month to month.
• Income. Your income normally won't change from month to month, but getting a raise or losing your job could affect your limit.
• Your credit score & report. Amex will regularly review your credit history, and red flags such as missed payments on other credit cards or loans will likely lead to a lower limit. So, you should keep tabs on it, too.

Along those same lines, Amex may not check your actual credit score every month, but you should. It's a good general indicator of your financial performance. The same factors that lead to a higher credit score will likely lead to a higher limit. And the reverse is true, too.

Unfortunately, you can never be sure what your American Express Premier Rewards Gold Card credit limit will be, but you can at least predict whether it will go up or down based on these factors.

Ultimately, it is worth noting that this card is no longer available to new applicants, but this fact doesn't impact existing cardholders.