If you only promise verbally or by email without signing the relevant offer documents of the other company, you will definitely have no legal responsibility! As for the reason for not going, it's really hard to say. You can find any reason. The other party is not stupid, but also human resources. This situation is bound to encounter a lot. As soon as you say it, he will understand! ! I think, just say we found a better one, there is no need to make up any other reasons.