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Should Canadian Patent Claims Simply Follow the Allowed U.S. Claims?

October 07, 2026

For many companies managing international patent portfolios, an allowed U.S. claim set becomes the natural starting point for prosecution in Canada.

There are good reasons for this. An allowed U.S. application can support expedited examination in Canada through the Patent Prosecution Highway (PPH), provided the Canadian claims sufficiently correspond to the allowed U.S. claims.

However, the allowed U.S. claims should not necessarily define the limits of the Canadian case.

U.S.-Specific Limitations May Not Be Necessary in Canada

Claims are often amended during U.S. prosecution to address issues that are particular to U.S. patent law.

This can be especially important for software, artificial intelligence, fintech, and other computer-implemented inventions. Limitations added to address subject-matter eligibility under 35 U.S.C. § 101, for example, may not be required under Canadian law. That said, Canada has its own requirements for computer-implemented inventions, and limitations that tie the claimed invention to improvements in computer operation or other physical effects can be valuable in both countries.

Prior-art considerations can also differ between Canada and the United States. In some cases, prior art relied on to support an obviousness rejection in the United States may not be citable in the same way in Canada because of subtle differences in the applicable law. As a result, limitations added to overcome a U.S. obviousness rejection may not always be necessary in the Canadian claims.

Before simply importing an allowed U.S. claim set, it can be worthwhile to ask why each significant limitation was added.

The Canadian Application May Support More

The underlying specification may support broader claims, alternative implementations, or commercially important subject matter that was not ultimately pursued in the United States.

That does not mean Canadian claims should always differ from their U.S. counterparts. In many cases, adopting the U.S. claims provides an efficient and effective route to allowance, particularly where accelerated examination is important. Pursuing broader claims may, however, mean foregoing the PPH.

The key is that alignment should be a strategic decision rather than an automatic one.

For important technology, the better approach is to consider the foreign prosecution history, understand why particular limitations were introduced, and assess whether Canadian law provides an opportunity to pursue meaningful additional claim scope.

Conclusion

An allowed U.S. claim set can be a valuable starting point for Canadian prosecution. It should not be treated as the finish line.

For important inventions, the better question is not simply whether the Canadian claims can be conformed to the U.S. claims, but whether they should be. A careful review of the U.S. prosecution history may reveal opportunities to pursue broader or different protection in Canada.

The goal should be to use the U.S. allowance strategically, not mechanically.