A Labour Market Impact Assessment (LMIA) is a document that an employer in Canada may need to get before hiring a foreign worker.
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A positive LMIA will show that there is a need for a foreign worker to fill the job. It will also show that no Canadian worker or permanent resident is available to do the job. A positive LMIA is sometimes called a confirmation letter.
If the employer needs an LMIA they must apply one
Once an employer gets the LMIA, the worker can apply for a work permit.
To apply for a work permit, a worker needs
a job offer letter
a contract
a copy of the LMIA, and
the LMIA number
(Source: IRCC)