Is the deadline to claim a missed input tax credit shorter for large businesses in Ontario?

Yes, generally. Certain categories of registrant that the Excise Tax Act treats as "specified" or "large," a status that depends on factors like the registrant's annual revenue and, separately, whether it's a financial institution, face a shorter time limit to claim a missed input tax credit than most small and medium-sized businesses do. A large registrant that discovers an eligible input tax credit it missed on an earlier return may find that window has already closed sooner than a smaller business would face for the identical situation.

This distinction is separate from Ontario's now-repealed recaptured input tax credit rule, which used to require certain large businesses to repay part of an ITC on specific categories of expense but was fully phased out by July 1, 2018 and no longer applies; the shorter ITC claim window discussed here is a different, still-current rule about how long you have to claim any credit at all. The two rules can both apply to the same large business and shouldn't be confused with each other.

Because the exact revenue threshold and rules defining a "specified" or "large" registrant, and the current time limits for each category, are the kind of figures that need to be confirmed rather than assumed, check your business's specific status and applicable deadline with a tax advisor.