You can determine what your VIN as there are VIN decoders. They have been posted on this forum. All you need is the last 5 digits. If you search for "2016 Tesla Model X VIN decoder" on the Internet. These VIN decoder will also determine the check digit.
Here is what each part of the VIN means:
Dropbox - ORG11230.pdf
My VIN for my 2016 Model X P90DL is: 5YJXCBE4?GF000??? The first ? Is the check digit, the last three digits is the last three digits of my VIN.
My insurance company did not recognize the VIN until my service center registered the car with the state (Florida in my case) DMV which took about three days.