Turbotax shows an unused RRSP contribution but I made none and my notice of assessment shows 0 for this. Where did turbotax get this value from?

If you imported your tax information using the CRA AutoFill My Return (AFR) service, you may have imported an RRSP Contribution slip that was received by CRA after you filed your tax return.

 

If this is the case, the unused contribution is automatically added to your return as a deduction. You can always verify your RRSP Contribution Room and previous history with CRA by signing into your online account.

 

Here's some more information you may find helpful: 

• TurboTax FAQ: Where can I find out how much room I have to contribute to my RRSP this year?
• CRA - Where can you find your RRSP deduction limit?