I belong to a tax exempt crafters guild and a major chain craft store will give our members a discount on all purchases if they provide the guilds' federal tax ID number. Are there potential problems with giving the number to 150+ people to use?

You are not giving it to all members, though Kate, you are giving it to the craft store so they can bookmark your particuler guild and access that tax number when members place an order so they can take the discount. It is business to business and done quite frequently.

Tick