A trade tribunal has ruled that Canada must pay the full fine for shipping too much softwood to the US.
Canada had offered to pay US$46.7m rather than the US$68m imposed by the London Court of International Arbitration.
By exporting too much wood it had breached the terms of the Softwood Lumber Agreement.
Provinces affected by the ruling include Ontario, Quebec, Manitoba and Saskatchewan. British Columbia and Alberta pay a higher tax and are unaffected.
The two countries ratified the softwood lumber agreement in 2006, bringing an end to years of wrangling over the volumes and pricing of Canadian softwood exported to the US.
