Do I need to post security with CRA to defer departure tax when I emigrate?

Sometimes, but not always. If you elect to defer paying the tax on your deemed capital gains until you actually sell the property, CRA can require you to post security — collateral guaranteeing the eventual payment — as a condition of allowing that deferral, particularly once the amount of tax involved reaches a meaningful level. Below that level, CRA generally doesn't insist on security at all, so many people with modest departure-tax bills can defer without posting anything.

What counts as acceptable security varies with the type of asset and the amount owing, and can include things like a bank letter of guarantee or a lien on specific property; CRA's administrative guidance sets out what it will accept, and this is worth reviewing well before your departure date rather than scrambling afterward. If security isn't arranged properly, CRA can refuse the deferral outright, leaving the tax due immediately.

Because arranging security can take time — banks don't issue guarantees overnight — this is one of the more practical, deadline-sensitive pieces of leaving Canada with significant unrealized gains. Getting advice on whether security will be required, and lining it up, before you actually emigrate avoids an unpleasant surprise on your departure-year return.