600 Travis, Suite 4200
Houston, Texas 77002
November 13, 2012
ONEOK Partners, L.P.
100 West Fifth Street
Tulsa, Oklahoma 74103-4298
We have acted as special tax counsel to ONEOK Partners, L.P., a Delaware limited partnership (the
Partnership), in connection with the offering and sale from time to time of common units representing limited partner interests in the Partnership having an aggregate offering price of up to $300,000,000 (the Common
Units), pursuant to the registration statement on Form S-3ASR dated August 13, 2012 (Registration No. 333-183287, the Registration Statement) filed with the Securities and Exchange Commission (the
Commission) under the Securities Act of 1933, as amended (the Act), and the prospectus supplement dated November 13, 2012 (the Prospectus Supplement). In connection therewith, we have
participated in the preparation of the discussion set forth under the caption Material United States Federal Income Tax Considerations in the Registration Statement, as updated by the statements in the Prospectus Supplement under the
caption Material Tax Considerations (the Discussion).
The Discussion, subject to the
qualifications and assumptions stated in the Discussion and the limitations and qualifications set forth herein, constitutes our opinion as to the material United States federal income tax consequences for purchasers of the Common Units pursuant to
This opinion letter is limited to the matters set forth herein, and no opinions are intended to be implied or
may be inferred beyond those expressly stated herein. Our opinion is rendered as of the date hereof and we assume no obligation to update or supplement this opinion or any matter related to this opinion to reflect any change of fact, circumstances,
or law after the date hereof. In addition, our opinion is based on the assumption that the matter will be properly presented to the applicable court.
November 13, 2012
Furthermore, our opinion is not binding on the Internal Revenue Service or a court. In
addition, we must note that our opinion represents merely our best legal judgment on the matters presented and that others may disagree with our conclusion. There can be no assurance that the Internal Revenue Service will not take a contrary
position or that a court would agree with our opinion if litigated.
We hereby consent to the filing of this opinion as an
exhibit to a Current Report on Form 8-K of the Partnership and to the references to our firm and this opinion contained in the Prospectus Supplement forming a part of the Registration Statement. In giving this consent, we do not admit that we are
experts under the Act or under the rules and regulations of the Commission relating thereto, with respect to any part of the Registration Statement, including this exhibit to the Current Report on Form 8-K.
Very truly yours,
/s/ Andrews Kurth LLP