You would have to start your tax return with the link provided by BMO; they most likely would have sent you an email. You will not be able to get the discount if you do not use that link. You may also be able to access this link through your work portal, if you are an employee of BMO.
See original post on TurboTax FAQs:
How do you get the 20% discount offered by BMO?
Thank you for choosing TurboTax.
Hello,
I am BMO client.
I got the promotion on my BMO account.
I used the link, but nothing happen when I made the payment.
Is it false/fake ads on official/legit BMO account ?
I already paid the full amount (using my BMO card) and the 20% hasn't been applied. Could you help me to get a refund of the difference ?
Thank you.
Please verify that the email associated to your account is still valid by answering YES or NO.
Thank you for choosing TurboTax.
Yes, email associated with my account is valid.
Thank you for help.
Here is the fix.
I am a BMO customer and I also went through the link and didn't get my discount. Here is what I did to get my discount.
Complete your tax return to the best of your ability.
Log out of Turbo Tax.
Go through the portal of BMO for your discount.
When you are on the opening page of your account, click make a copy of your previous completed return.
Open the copy and navigate to the pay page. The discount should now appear.