Since tax year 2020, there is a difference between a license code (for Desktop) and an activation code (for Online). This error code 606 means you are trying to enter a code for TurboTax Online in desktop software (or vice versa).

We understand, sometimes, this can be confusing, but on the box (or on the retailer website), you have to choose between TurboTax Online and TurboTax Desktop. They are not the same software, and codes from one cannot be used in the other one.

If on the box it's TurboTax Online, you can activate your code to your account on this link. 

Link: https://shop.app.intuit.com/activate?rootProfile=ca&locale=en-ca

If on the box it's TurboTax Desktop, you can download/install your software from this link.

link: https://turbotax.intuit.ca/tax/software/download

If you bought the wrong version, you can get a refund and then buy the one you need. by using this form to get a refund. (LINK: https://turbotax.community.intuit.ca/turbotax-support/en-ca/help-article/taxation/get-refund-turbota...). Make sure to add a clear photo of your receipt, showing the name of the store, the date, the product bought, and the price paid.

Thank you for choosing TurboTax.

I would the premier addition at costco today and when I enter the code I get error 606

@prm0073 Please make sure that you have purchased the right product. The codes for TurboTax Do It Yourself (Online) will not work with TurboTax Desktop & vice-versa.

If you bought the wrong version, you can get a refund and then buy the one you need. Use this form to get a refund: https://turbotax.community.intuit.ca/turbotax-support/en-ca/help-article/taxation/get-refund-turbota...

I seem to have the right product as far as I can tell.

@prm0073 Please contact our phone support team as they will be able to assist you further.

On my purchased said Deluxe Online Edition , not Desktop  and that is confusing 
Online means for many that you are downloading / register online 🤔
and error 603 said no more than 3 computer , how could be when I only have one

@user17738619640 If you have bought TurboTax Online, please go to turbotax.ca/activate to use your code before you start your returns. You can see this TurboTax FAQ for step-by-step instructions: In TurboTax Online, how do I use a prepayment code? 

Please keep in mind that the code can only be used once per account. Using the code again will result in an error message. It can only be linked to one account. Additionally, TurboTax Online and TurboTax Desktop codes are not interchangeable. 

Thank you for choosing TurboTax.