Article 67 governs the deduction of head office expenses for permanent establishments (PEs) in Oman. PEs can deduct costs allocated by a foreign head office or related party, such as technical consultancy, R&D, data processing, and general administration. However, these deductions are strictly subject to the percentages and rules defined in the Executive Regulation of the Law and must comply with the general 'income production' rule of Article 54. This provision ensures that foreign branches can claim their fair share of global overheads while preventing the artificial erosion of the Omani tax base through excessive management charges.