12.3 Each Party agrees that it will upon written demand of the other Party deliver to such other Party (or to any government or other Taxing authority as such other Party directs), any form or document and provide such other cooperation or assistance as may (in either case) reasonably be required in order to allow such other Party to make a payment under this Agreement without any deduction or withholding for or on account of any Tax or with such deduction or withholding at a reduced rate (so long as the completion, execution or submission of such form or document, or the provision of such cooperation or assistance, would not materially prejudice the legal or commercial position of the Party in receipt of such demand). Any such form or document shall be accurate and completed in a manner reasonably satisfactory to such other Party and shall be executed and delivered with any reasonably required certification by such date as is agreed between the Parties or, failing such agreement, as soon as reasonably practicable.