The Official letter No. 2534/TCT-CS dated 18 July 2012 of GDT about VAT
According to point 4.7 Appendix I, debit notes issued together with Circular No. 194/2010/TT-BTC dated 06 December 2010; point 1.3.c, section III, part B of Circular No. 129/2008/TT-BTC dated 26 December 2008 of MOF; point 3.b8, article 16 of Circular No. 06/2012 dated 11 January 2012:
In case, amounts paid by bank transfer are lower than the amounts must pay under contracts or appendix of contracts, sellers which can explain the reasons, commitment responsible for law about declaration considered payment by bank transfer. Sellers declare, deduct input VAT of the sold goods if satisfying the conditions point 1.3.c, section III, part B of Circular No. 129/2008/TT-BTC dated 26 December 2008 of MOF.