I went through all of the work and experience at a previous job to get my Professional Engineer's license, however, my new firm is not licensed to provide design services. Is it still allowable to place "P.E." after my name since I am a licensed professional engineer even though I will not be providing sealing and stamping of documents? I know some engineers will get their licenses even if it is not required, but I wasn't sure how this lined up with presenting your credentials on a business card.
If you put PE on your card, it suggests that you are able to sign off documents right now. (I assume that even if you wanted to do that outside your employment, you aren't paying for professional indemnity insurance since you don't need it for your job, so that would NOT be a good idea...)
Just make sure you don't mislead somebody about what you (or your employer) can do, and they file you (or your employer) under "P" for "pretentious time-waster" when they find out it's not true :)
You worked for it, it represents a level of skill relevant to your "trade" so it belongs on your card.
If you wish to not mention it, that is your choice and you may have good reason for that.
I had a colleague who has a PhD and does not mention it... But the work does tend to give the game away....