These characters combine to literally mean “empty/unbacked payment slip,” which is the perfect description of a financial check that will bounce. This powerful literal image is then applied to any promise that lacks substance.
In Chinese culture, personal and professional relationships are built on a foundation of 信用 (xìnyòng) - trustworthiness or credibility. Making a promise and keeping it is fundamental to maintaining one's 面子 (miànzi) - “face” or social standing. Giving someone a `空头支票` is therefore a serious social offense. It signals that you are unreliable and untrustworthy, severely damaging your `信用`. This can have long-lasting consequences, as people will be reluctant to cooperate with or believe you in the future. While Western culture has similar concepts like “empty words” or “writing checks you can't cash,” `空头支票` is a much more common, everyday metaphor in Chinese. The Western phrase often implies boastful arrogance (“his ego is writing checks his body can't cash”), whereas `空头支票` is used more broadly to describe any promise—big or small, boastful or seemingly sincere—that is ultimately not met. It focuses more on the deceit and the disappointment of the recipient.
This term is versatile and appears in many modern contexts.
The term is almost exclusively negative and implies a degree of intentional deceit or gross irresponsibility on the part of the promiser.