How long or well do you have to know a person before they are considered to be personally known to you for you to notarize them without identification? This is a very gray area. If you met them once or twice, then forget about it. You will not remember them a few years later if you are in court. If you have known the person for five years seeing them every day, then you clearly know them. But, what if you see them in the hall frequently, but don't really know exactly who they are? You should have met a person many times in association with others and have heard their name many times from other people to know who they are enough for you to consider them to be personally known. I would recommend that you should have met a person at least eight times and have heard their full name stated by others many times to consider them to be personally known.