Consumers aren’t the only ones feeling the credit crunch these days – credit card companies are also hurting for cash. Rising defaults and tighter debt markets have caused credit card companies to make several changes to cover themselves. The most recent: Cutting spending limits on credit cards.

Some consumers may be caught off-guard this holiday season as credit card companies slash credit card limits, often without warning their customers. American Express, Bank of America, Citibank and Discover are among the major credit card issuers taking such actions.

So, who is at risk of having their limits slashed? The first targets will likely be those who have high balances along with those who have low credit scores and are not paying their bills on time. These high-risk accounts can quickly cause problems for issuers if they default.

However, the unprecedented crisis is also causing problems for many consumers with good credit ratings. This means that credit card companies may also begin to target these consumers that they perceive as high-risk in today’s environment. As a result, consumers should keep their balance 30% lower than their limit to reduce the odds of such reductions.

The other key thing for consumers is to check these limits on a regular basis. Accidentally going over the limit on a credit card can spur a substantial amount of fees and charges. Consumers that already hit this wall may want to call up their credit card company saying that they didn’t know it was lowered.