How long are claim codes good for?

I’m building an app that will manage the softap process for customers of my product.

I’m worried that the customers will (after they get the hang of setting up devices) connect to wifi before launching the softap wizard in my app. This presents a problem because my app logic attempts to request a claim code from my server side, but this request can only happen if the user’s mobile device has internet access.

My thought was to request a claim code and just keep one in reserve for the customer, is this a valid approach? Will the claim code ever expire? Can I use the same claim code more than once?