Official letter No. 3771/TCT-CS October 29, 2012 of the General Department of Taxation about tax policy contractor guide
According to 3.1.b2 Section III, Part B of Circular No. 134/2008/TT-BTC dated 31 Dec 2008 of the Ministry of Finance:
In case, foreign contractors sign contracts with Vietnamese subcontractor or foreign subcontractor paying tax under Section II of Part B of this Circular to share a part of the value of the work specified in the contract signed with Vietnamese party, taxable revenue of the foreign contractors do not include the value of work, the value of machinery and equipment done by Vietnamese subcontractors or foreign subcontractors....
This provision shall not apply in the case of foreign contractors signing a contract with suppliers in Vietnam to buy goods and services for the implementation of the contract.