SIN Number changed what to do?

[pretendthisisaname]

Hello everyone,
I received my CoPR as headed to the border to land. I have an old SIN number with a '9' that has expired before I landed...I applied for a new SIN number and got one with a '5'. I was working as a customer service agent with my '9' SIN number for one month, before it expired and I had to leave Canada. Do I
1. Have to file my taxes for the old SIN number even though it has already expired?
2. Does the CRA know about my old SIN number , because ServiceCanada told me that the old SIN number has expired and is now useless.

 

[APPNOV2014NY]

1. Yes, you can filed taxes with old expired SIN number.
2. Yes. CRA knows. Your expired temporary SIN is linked to your new permanent SIN.

 

[sid1987]

baaaaaaaaaaaa... i was in the same boat.. don worry CRA knows.. its all in system don worry... i filed my taxes got all my refunds

 

[sistemc]

AFAIK CRA instructions are to always use the latest assigned SIN number when filling taxes.

And don’t worry, CRA knows to link your SIN numbers.