Everyone I know does the second they get the letter. Just because you don't have a number yet doesn't mean you're not a PE- as long as you passed everything, what's the problem? Like you said, you're not stamping anything, so who cares?
Notwithstanding the previous statements of other posters, consider this:
1. Passing an examination is not tantamount to holding a license. The State Board (to whom you applied) ultimately has the discretion and authority to license you as a Professional Engineer.
2. Once you have obtained licensure as a Professional Engineer within a jurisdiction (state), those rights and privileges to practice engineering are
LIMITED to that jurisdiction (e.g. many states out-right prohibit the use of 'engineer' in the title if you are not licensed in that state).
3. In order to practice engineering in a different jurisdiction, you must apply to the new jurisdiction's licensing board and meet the requirements of THAT jurisdiction. In some cases, the requirement may differ (
e.g. degree requirements, years of experience, specialty exams,
etc.) to the point where you may have to offer more in order to obtain that license.
4. Licensure as a Professional Engineer in other jurisdictions is NOT PRESUMPTIVE once you have passed the NCEES examination - you must meet any other criteria that the jurisdiction licensing board requires.
5. Most states PROHIBIT the usage of Professional Engineer or similar terms that convey a sense that you are licensed under the jurisdictions statutes and rules when using a title in correspondence. As an example, in Florida, Florida Statute 471, F.S. states ..
471.003(1) No person other than a duly licensed engineer shall practice engineering or use the name or title of "licensed engineer," "professional engineer," or any other title, designation, words, letters, abbreviations, or device tending to indicate that such person holds an active license as an engineer in this state.
The bottom line here is that I am really not try to bust anyone's balls - I am only pointing out that which your state board would tell you if you were to send them an e-mail with P.E. in the title as you were waiting for results or your license or seeking comity with that state (jurisdiction).
Everyone here (and especially ME) wants to share in your accomplishments and celebrations for what is THE culmination of A LOT of hard work. Everyone at this board understands and appreciates what it means to call yourself a P.E. My point is just to use a little discretion so you don't find yourself running afoul and in an akward position with your state board. If you find the licensing process to be too inane for your liking - try the disciplinary process for breaking a rule (or statute)! They take those things seriously.
Last thought (promise):
I am proud of everyone who obtains thier license and knowing that I have been able to help so many down the road to licensure. It is one of the primary reasons I participate at THIS board. While I am very knowledgable about engineering subjects and help many through exam types of issues, I feel it is equally important to address potential professional and licensure issues. While the members of this board are happy to recognize the 'P.E.' achievement after you receive your exam results - caution should be used in correspondence before you have actually received your license.
Best regards,
JR