Sole Source Letter

Letter certifying that the ITHAKA products/collections are not available from any other single source.
JSTOR Sole Source Letter
Portico Sole Source Letter
Artstor Digital Library Sole Source Letter
JSTOR Forum Sole Source Letter

Form W-9

An official statement from an entity of their Tax Identification Number and Certification. Participants may rely on the information on the form for their records and/or reporting needs.

Ithaka Harbors Inc.

Certification of U.S. Tax Residency

Many U.S. treaty partners require the IRS to certify that the person claiming treaty benefits is a resident of the United States for federal tax purposes. The IRS provides this residency certification on IRS Form 6166, a letter of U.S. residency certification.
ITHAKA Certification of U.S. Tax Residency

Payment Instructions

Account, routing and address information for participants paying an invoice by check or wire transfer. There is also a web form for participants paying an invoice by credit card.
Institutional Payments

Looking for something else? Please contact us with your request.