状況によって違うらしいですから、コンタクトする必要があります。
http://www14.hrdc-drhc.gc.ca/ns-sn/sin-nas/030_e.shtml#q10にかかれています。
10 - What do I do if my SIN card is lost or stolen?
If your SIN card is lost or stolen, contact us. We will be able to provide guidance as to applying for a SIN card, based on your individual circumstances.
コンタクト先
http://www.hrdc-drhc.gc.ca/sin-nas/020_e.shtmlTelephone:
Please refer to the Government of Canada pages of your local telephone directory, under the heading Social Insurance Number. There is no charge for this call. Our commitment is to provide service from 8:30 to 4:30, local time.
If you are calling from outside Canada, the number is (506) 548-7961.
Address:
Social Insurance Registration
P.O. Box 7000
Bathurst, NB
E2A 4T1
Email:
sin-nas@hrdc-drhc.gc.ca