In a May 31, 2018 Tax Court of Canada case, the taxpayer claimed ITCs (arising from the December 2008 quarter-end) which were previously disallowed when claimed by a related party. Within 30 days of that decision, the taxpayer claimed the ITCs on their return for the quarter ending September 30, 2015.
ITCs must be claimed within four years after the end of the reporting period in which they arise. It was not relevant that the related party had attempted to claim the ITCs within that period. Failure to make the claim on a return filed within four years of the end of the appropriate period was fatal to the claim.
Action Item: Ensure you are claiming your input tax credits in a timely fashion or risk losing them altogether.