Can I add a deduction that was refused by H&R block that I know for a fact I can claim?

[winger1316]

Filed in 2018, and was told that I cannot claim a certain deduction even though I had claimed it years previous, and I printed off the reason why I can claim it straight from the government website. still refused and wouldn't add it as a deduction. probably about $3500 lost on that tax return cause of it (personal taxes). Can I go back and claim that now and is it worth it to pay to file for that update?

[TurboTaxGinette]

TurboTax has created an FAQ link to help you make your amendment. Be aware that the Canada Revenue Agency(CRA) suggests waiting for your Notice of Assessment(NOA) before making any changes as the assessment may have already corrected the amount left out. Please follow the link included below.
I have filed my tax return. Can I still make changes?

The CRA also has a link with information about Change My Return which you can use through My Account once you have received your NOA. 

Thank you for choosing TurboTax.