SASK Grad Retention Program

Typically if a slip relates to a previous tax year, as this one clearly does, you should be filing an adjustment for that year to claim it.  You will need to ask the client how they filed their 2017 tax return (e-file, netfile, paper).  If they filed it electronically (e-file or netfile), you can use their 2017 Assessment Details breakdown (downloadable from the Represent a Client web portal) to recreate the tax year in Profile.  Take a Snapshot of the completed form  (Audit men => Snapshot), then enter the new tax slip.  You can then open the form T1-ADJ, right click in the line numbers section and select the option to apply changes based on the snapshot you created.  The T1-ADJ will populate with the changes, showing the changes affected by this $3,000 credit.
You can then open the T1Refile page to select that you are Re-filing this return  (The T183 will now show T183R).  Have your client sign the T183R, and you should be set to Refile her return.   Hope this helps.