If you need to postpone or cancel plans with someone then you can take a rain check. We use this expression when we want to politely decline an invitation or reschedule a plan, but also imply that we would be interested in accepting another one in the future. When you take a rain check on something it lets the other person know that although you are unable to accept their offer or participate in an activity now, you are hopeful that it will work out next time. It shows a willingness to reschedule for a later date.
This is an informal expression that is most often used in spoken English. It can be used with people that you have a casual, friendly relationship with. In terms of form, you can use it in a statement, such as "I will have to take a rain check on (activity)", or as a question, such as "can we take a rain check on (activity)?" For example:
Do you mind if we take a rain check on our dinner plans tomorrow night? I'm not feeling well.
I just found out that I have to work late tonight, so could we take a rain check on our movie date this evening? The movie's playing again tomorrow night so we could go then if you're free.
A. I’m going skiing this afternoon. Do you want to come?
B. I would love to but I’ll have to take a rain check because I already have plans today. Thanks for the offer though!
Did you know? This expression originated in the late 19th century and relates to sports. If a sporting event was cancelled due to rain, spectators were given a rain check which enabled them to receive a refund or gain access to another event.