If I have received a T4A, when I do REFILE is the only thing I need to do at the slip and then submit? Is the refund amount shown the new refund amount or the additional?

[TurboTax-Duncan]

Hi, thank you for using Intuit Turbo tax AnswerXchange

Turbo Tax has a great reference for refile:

https://turbotax.community.intuit.ca/community/tax-topics/help/what-is-refile/00/873779

You should definitely refile when you receive additional slips/ information after you file your tax return for the tax year. You can refile anytime after you receive your Notice of Assessment from your original filing.

When you refile you add information to your return and TurboTax will recalculate the whole return based on the original plus the added information. The  whole return is then sent to the Canada Revenue Agency (CRA), not just the added information.

CRA will send a notice of Reassessment (NoA) after they process the refile. This will show the results before and after the new information is added. The NoA will show the result of the added information; either a refund or balance due.

Hope this helps