Is it permissable to run "test claims" in retail pharmacy?

Sometimes patients will call and ask us what a medication costs though their insurance. However, they don't have a prescription on file. Is it permissible to run a fake rx through to see what their copay is, then reverse it? I've had another pharmacist say that the insurance companies don't like it when we do test claims with out an actual prescription on file.
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums