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Harbor Maintenance Tax Credit

This credit may reduce your corporate excise due. Learn if you qualify.


The Harbor Maintenance Tax Credit may be available to corporate excise taxpayers who paid the federal harbor maintenance tax (HMT). The HMT is a federal tax on the use of ports in Massachusetts.


The credit isn’t available for taxes paid with respect to:

  • Passengers
  • The shipment of bulk cargo, or
  • The shipment of any other cargo or item of commerce not included in the meaning of "break-bulk" or "containerized cargo.”

To show the HMT was paid, taxpayers must retain documentation including:

  • U.S. Customs Form 349
  • Customs Form 7501.

Minimum excise, maximum amount of credits, and carryover

The HMT credit may not reduce the corporate excise due below $456. The credit isn’t subject to the 50% limitation of Massachusetts General Laws chapter 63, section 32C.

Any unused credit may be carried forward for the next 5 tax years.

Additional information

For more information about the credit, important definitions, and details on the taxability of shipments: