How PR Status Is Lost
Breaking residency requirement (gone 2+ years), criminal conviction, misrepresentation on application. Once lost, you're no longer PR.
Re-establishing PR
You can reapply for PR through normal channels. Full application process again. This resets your citizenship clock—you'd need 3-5 more years after regaining PR.
If Revoked for Misrepresentation
IRCC bars future applications (usually 5 years minimum). Legal challenge possible with lawyer.