No, not sin, Social Insurance Number (s), that SIN.

If the Social Insurance Number is simply a number given out each time a Canadian asks for one, the Maximum number of encodings is simply `999,999,999` codes. That seems like a very large number and why would anyone worry about running out of numbers in this program? The Social Insurance Number has become the de facto standard for identification in Canada (especially financially), and a number to be guarded closely, so each number is very important.

Some points to think about this number:

- I don’t think anyone has the Social Insurance Number
`000 000 001`or anything like that encoding, so there aren’t as many numbers as we think. Is the exact number of available SINs published anywhere? I don’t think it is, but maybe I missed out on that. - From
**1973**to**1994**the three digit prefix (the first three numbers) increased by about`265`(if I compare my SIN to my children’s SIN), so not an insignificant increase. From 1994 to 2005 the prefix digits increased by`035`. This assumes that the numbers are allocated in an increasing order. - There are no more plastic SIN Cards being made, you simply get a letter with your SIN and that is it!
- Given
`900`SIN were lost with the Heartbleed bug, how many more digits are lost due to identity theft and such? - Is there a recovery program for digits after someone dies? I don’t think so.
- Temporary SINs have
`9`as the first digit, and depending on where you apply your leading digit will reflect that (see Wikipedia for this) - There is a checksum to easily figure out if a SIN is real or bogus.

## Fear Monger?

Am I just fear mongering now? It’s possible, but I just wonder if we are going to hear in about 20 years that the Social Insurance Number will go from being a 9 digit number to either:

- A 9 digit hexadecimal number (base 16) (e.g.
`DEA DBE EF9`) - A 12 digit regular number

Those would be simple fixes I suppose, except then every and any program that used the SIN for identification would need to be recoded (can you say Y2K ?) .

I know this is an old post, but I wanted to comment and say that there are 90 million possible valid SINs, with 10 million SINs for each starting digit from 1-9. Excluding temporary residents who receive SINs starting with a 9, that leaves 80 million possible SINs for Permanent Residents and Citizens. The population of Canada as of 2017 was 37 million, and projected to be 43-68 million by 2061 (statcan). It doesn’t seem likely that we will run out of SINs for a half century even with aggressive population growth estimates.