Hi @Abidaisyf
If you switch to a Canada-US plan, there will be no extra charges when using your phone in the US (some exceptions apply, please check the link shared below for more details)
This covers calls made and received in the US and Canada, outgoing and incoming text messages and data.
Calls made to other countries other than the US or Canada are not covered by the Canada-US plan.
You can still switch back to a Canada-only plan once you return, however, your current plan might no longer be available. You should still be available to select a different Canada-US plan if your old plan is no longer available.
Please check this article for more details about Canada-US plans https://www.koodomobile.com/en/help/traveling-with-your-canada-us-rate-plan?srsltid=AfmBOoo-Gi49YVLzK2uzGe2MCfpCYaMcGD1k5FVDxMNJrRltv-NxEwt1