NYSE: RIG 2.915 0.135 4.43% 1:02 P.M. ET Transocean MENU OUR HISTORY Today's Transocean is the modern descendant of the world's most innovative and successful deepwater drilling companies, and the pioneering people who made them great. A LEGACY OF BOLD LEADERSHIP For generations Transocean and its legacy companies have led the offshore drilling industry with the most innovative and sophisticated technology, and the people that put it to record-setting use. From the first mobile jackup rig and the first drillship, both in the 1950s, to the 2016 drillships that incorporate our designed and patented Active Power Compensation® hybrid system, we're are still pushing the curve. 1920s Transocean traces its roots to onshore drilling operations, where T.S. "Stoney" Stoneman began his career as a draftsman and then a landman before joining the Danciger Oil & Refining Company of Fort Worth, Texas in 1926. Mr. Stoneman bought the company's first drilling rig, paying for it with a personal check and putting it on his expense report. He would later play key leadership roles in pioneering offshore drilling with The Offshore Company. 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s BACK TO TOP Transocean ABOUT CONTACT ©2021 TRANSOCEAN LTD. LEGAL/PRIVACY NOTICE

NYSE: RIG 2.915 0.135 4.43% 1:02 P.M. ET Transocean MENU IRS FORMS 8937 The information contained herein and in the attachment does not constitute tax, accounting or legal advice and does not purport to be complete or to describe the consequences that may apply to particular categories of securityholders. Transocean does not provide tax, accounting or legal advice. Any tax statements contained herein and in the attachment were not intended or written to be used, and cannot be used, for the purpose of avoiding penalties imposed under the Internal Revenue Code. You are urged to consult your own tax advisor regarding the particular consequences of the distribution to you, including the applicability and effect of all U.S. federal, state, local and foreign tax laws. IRS Form 8937 - New Notes IRS Form 8937 - Exchange Offers - 2020 IRS Form 8937 - Exchange Offers - 2021 IRS Form 8937 - Ocean Rig Acquisition IRS Form 8937 - Songa Compulsory Acquisition IRS Form 8937 - Songa Voluntary Acquisition IRS Form 8937 - 2016 Distributions IRS Form 8937 - 2016 Merger IRS Form 8937 - 2015 Distributions IRS Form 8937 - 2014 Distributions STATEMENTS Statement under 1.1273-2(f)(9) - New Notes BACK TO TOP Transocean ABOUT CONTACT ©2021 TRANSOCEAN LTD. LEGAL/PRIVACY NOTICE

NYSE: RIG 2.915 0.135 4.43% 1:02 P.M. ET Transocean MENU SHAREHOLDER INFORMATION Transfer Agent and Registrar Computershare www.computershare.com/investor Shareholder inquiries should be sent to: Computershare P.O. Box 505000 Louisville, Kentucky 40233-5000 1 877 397 7229 1 201 680 6570 (for callers outside the United States) Overnight correspondence should be mailed to: Computershare 462 South 4th Street Suite 1600 Louisville, Kentucky 40233-5000 Online inquiries: https://www-us.computershare.com/investor/contact BACK TO TOP Transocean ABOUT CONTACT ©2021 TRANSOCEAN LTD. LEGAL/PRIVACY NOTICE