Upcoming National Meeting

2025 Canadian Tax Workshop For U.S. Companies

The COST Canadian Tax Workshop for US Companies covers the key tax issues U.S. companies who are doing business with Canadians or in Canada need to know. The primary focus of the Workshop will be on GST, HST and Income Tax but will also cover QST, Payroll and Property Taxes. Attendees will also participate in an interactive audit session covering Canadian tax issues that they’ve been dealing with.

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Newsletters & Media

Legislative Alert

ISSUE 25-36; October 8, 2025

COST Opposes Massachusetts Legislation Seeking to Tax Foreign-Source Income Without Foreign Factor Representation; COST State Regional Leads for Legislative Advocacy

Cost Conscious

ISSUE 25-20; October 10, 2025

Transition Planning & COST Engagement – How important do you believe it is for a successor or replacement team member to begin engaging with COST early in their transition?

Featured Resources

COST - Council on State Taxation

Amicus Briefs

Pacific Bell Telephone Company et al. v. County of Napa, et al.

COST has filed an amicus letter in Pacific Bell Telephone Company et al. v. County of Napa, et al., urging the California Supreme Court to grant review and provide clear guidance on the California constitutional provisions governing the assessment and taxation of utility property.

COST - Council on State Taxation

COST Studies, Articles & Reports

2025 State and Local Amnesty Programs

Tracker of most state and local tax amnesty programs enacted and conducted in 2025.

COST - Council on State Taxation

COST Comments & Testimony

Testimony in Opposition to S.204 - Creation of Tax Haven Blacklist

COST submitted testimony in opposition to Massachusetts S.2041, a bill that would create a list of foreign jurisdictions in which a corporation is presumptively incorporated for purposes of avoiding Massachusetts’s corporate excise tax.