Here is a great TurboTax article about how to use Audit Defence in TurboTax ? 

Audit Defence is used when CRA investigates on your taxes files. When you have Audit Defence option, we (TurboTax) represent you and answer all questions asked by the CRA. 

If you're using a CD/download version of TurboTax, locate the side menu and select the option for Review, then scroll down to select Audit Defence. From there, you can choose to arrange a callback or schedule an appointment with a tax expert. Use your Intuit Account to sign in to TurboTax.

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