http://www.legislation.gov.uk/ukpga/2006/37/section/5Parliamentary Costs Act 2006An Act to consolidate the House of Commons Costs Taxation Act 1847, the House of Lords Costs Taxation Act 1849, the Parliamentary Costs Act 1865, the Parliamentary Costs Act 1867, the Parliamentary Costs Act 1871 and the House of Commons Costs Taxation Act 1879, with amendments to give effect to recommendations of the Law Commission and the Scottish Law Commission.texttext/xmlenStatute Law Database2014-02-18Expert Participation2011-12-23 51Subsection (2) applies where—athe taxing officer of one House receives an application under section 3, andbthe bill of costs to which the application relates includes costs which relate to a private Bill but not to proceedings of that House.2The taxing officer may—aassess the costs himself, orbask the taxing officer of the other House or an authorised court officer to assess some or all of them.3Subsection (5) applies where—aan officer is asked under subsection (2)(b) to assess costs, orbthe Secretary of State asks the taxing officer of the House of Commons to assess costs relating to a Bill or to a provisional order.4Subsection (5) also applies where an authorised court officer asks either taxing officer to assess costs—arelating to a private Bill, andbincluded in a bill of costs which the authorised officer is directed to assess by the court by which he is authorised.5The officer concerned must—aassess the costs, andbgive his opinion to the person who asked him to assess them.6An authorised court officer may—afor the purpose of assessing costs under this section, exercise any powers he has for the purpose of assessing costs under his authority, andbreceive fees for assessing costs under this section on the same basis as he would for assessing costs under his authority.7“Authorised court officer” means an officer of a court who is authorised by that court to assess costs relating to its proceedings.