My understanding is, that number is yours, you were tested and achieved a passing score. That entitled you to recieve a number. You can use it for any of your personal dealings that you may like to under take. I'm currently the quilifying party for the company I work for but I also have another business that I use my license to file jobs agiainst and have never found it to cause any issues.
However I don't think I would have my number printed on all these public documents. Just seems to me that you maybe setting yourself up for someone to forge you name and use you number. If it can happen with a credit card whats to stop them from doing the same here.
