It makes sense to me but I'd probably cap it at one level above what was purchased as the higher rating ones are supposed to have DNA, medical records etc in them and no amount of paying for bus rides is gonna replicate that
No, they ALL tie back to a database, that has every detail of your life, INCLUDING a DNA sample. Everything and anything that can be tracked is tied to your SIN. Where you were born, what childhood diseases you had. What school you went to, AND your grades (including all your 'participation' trophies from the Science Fairs). Every job you have had*. (If they are not the ones issuing the SIN in the first place. Any criminal infractions, any tickets, licenses, bank accounts, rental agreements... it ALL ties back to your SIN...
Which is why there are ratings. A fake SIN, could be one of several types:
A legal SIN that has been somehow copied and is now in circulation.
A totally made up SIN inserted by way of a black market organization.
Thus, the Higher the rating, the closer you match all the info on the SIN, at a casual glace. (a GOOD scanner, like those used at police stations will find the fake SIN eventually).
Thus, If you are, say an Male African Troll, having the totally real and legal SIN of a Female Asian Dwarf is not a good match (Rating 1)...
Or a crappy black market SIN might have used the DNA of a chicken for the Bioinformatics... (again Rating 1)
Now, for most small things that require a SIN, that no one really cares about.... you're going to do fine. No one cares about your SIN for riding the bus (although technically you need a SIN) Or if you're buying a soykafe from a vending machine. (In fact, one make even argue the scanner for many of these annoyance scans are probably broken!)
I'm going to say that again. No One Cares How Many SoyKafes You Bought.
You do know what they care about? How many $5000+ purchases you have made! (You can't escape the advertisers!! You ARE Horizon's Money Puppet. Just admit it!)
But the more expensive the item, the more security on the check.. (AKA the higher the rating of the scanner)
And, at the end of the day... when that scanner requests a biosample, and you don't match what's on file...