Typically, you can apply for new credit cards while unemployed. However, doing so may have a two-fold effect on your credit profile.
First, when you apply for a new credit card or account, banks or lenders usually make a hard credit inquiry to assess your financial reliability, which may cause your credit score to temporarily drop by a few points. If multiple requests for the same product—like credit cards—appear in a short timeframe, the first inquiry may be the only one that affects your score.
Second, if you’re approved for the credit card, opening the new account may cause another drop in your credit score. Having recently opened new or multiple credit accounts may also cause potential lenders to view you as a risky borrower.