The Meaning Behind a 900-Series Canadian SIN Number, and Who Gets One
Ever wondered why a colleague mentions their SIN starts with a 9, while everyone else’s just seems to start with anything else? It isn’t random, and it isn’t a coincidence — it’s Canada’s way of building someone’s immigration status directly into a number they’ll use at every payroll run. Here’s the 900 series sin number meaning, worked through with a realistic example.
What a SIN actually is
Every worker in Canada needs a 9-digit Social Insurance Number to be paid and to access government programmes. Service Canada no longer issues plastic cards — you get a confirmation letter, and once you know your number you can view and print it any time through My Service Canada Account.
The example: Naledi’s first year on a work permit
Say Naledi lands in Vancouver on an open work permit that’s valid for two years. Within her first week she applies for a SIN online, using her work permit as the primary document plus her passport as a secondary one. Because she’s a temporary resident, not a permanent resident, Service Canada issues her a SIN beginning with the digit 9 — a 900-series number. Everything after that first digit works exactly like anyone else’s; the “9” itself is the entire signal.
That signal means her SIN expires alongside her work permit. If her employer sponsors an extension eighteen months in, and she’s granted a further permit, her SIN doesn’t renew itself automatically — she has to actively update its expiry date to match the new document. Miss that step, and payroll systems will simply stop being able to pay her, because as far as the system is concerned her authorisation to work has lapsed, whether or not her actual permit has.
Contrast: what happens once Naledi becomes a permanent resident
When Naledi’s Express Entry application is eventually approved and she lands as a PR, she doesn’t renew her old 900-series number — permanent residents and Canadian citizens hold a regular SIN that never expires, full stop. The 9-prefix genuinely only ever applies to temporary status; the moment that status becomes permanent, the number’s whole logic changes.
The practical mechanics, for anyone applying
There’s no fee to apply for a SIN under any status — a website charging you for this is running a scam. Anyone 12 or older can apply for their own, a parent can apply for a child, and a legal guardian can apply on behalf of an adult in their care. Applying online typically takes about five business days once your documents are complete; by mail, closer to twenty. Service Canada cannot give you your number over the phone, so don’t expect a shortcut there.
The one thing this file doesn’t confirm either way is whether a newly landed permanent resident can start the online SIN application from abroad, in the gap between receiving a Confirmation of Permanent Residence and physically landing — so don’t plan around that assumption until you’ve checked directly with Service Canada.
For how any of this interacts with your own permit renewal timeline, that’s worth raising with a licensed RCIC alongside your immigration paperwork, since a lapsed SIN and a lapsed permit are two related but separate problems. Cape2Canada’s settlement checklist spells out this 900 series sin number meaning right alongside a broader temporary resident sin number explained walkthrough, because it’s the kind of admin detail that’s easy to forget mid-move.