Official registration numbers, such as Swedish personal identification number, or "personnummer" (date of birth + serial + checksum [Luhn], where even serials are used for females and odd for males):
- It can take a few days before a newborn is assigned a number
- Non-citizens don't have one, but they can get a coordination number on the same format but with the date part incremented by 60 days.
- Citizens can have both a coordination number and a personal identification number in certain cases.
- They can be changed if the wrong birth date or gender registered at birth or during immigration, for protected identities, or for gender transitions.
In the Netherlands we have something similar: the BSN (translated: citizen service number). This used to be the social security number, but because it was used by an increasing number or government agencies unrelated to social security it was changed to BSN.
One of the major problems with this number is that it has a special status under the law. There are very strict rules as to who can process and/or store this number and for which purpose. For example: a bank can process this when opening a bank account, under anti money laundering regulations, but they cannot use it to identify an existing customer.
If you originally set up your database to use SSNs you now have a problem. This actually happened with our chamber of commerce: if you registered a one-man business they used the SSN as the business id and you’re required as a business to publish this. Now it’s suddenly a number that is subject to strict privacy rules and they have to renumber all one-man businesses.
So that’s another problem with data you don’t control: the legal status of this data can change.
- It can take a few days before a newborn is assigned a number
- Non-citizens don't have one, but they can get a coordination number on the same format but with the date part incremented by 60 days.
- Citizens can have both a coordination number and a personal identification number in certain cases.
- They can be changed if the wrong birth date or gender registered at birth or during immigration, for protected identities, or for gender transitions.