council decis octob authoris portug appli measur derog articl sixth direct eec harmonis law member state relat turnov tax ec council european union regard treati establish european commun regard sixth council direct eec harmonis law member state relat turnov tax common system ad tax uniform basi assess articl thereof regard propos commiss letter regist commiss februari portug request authoris introduc derog measur respect doorstep sale sector member state inform thereof march portug notifi march commiss possess inform need decis matter measur intend enabl firm engag doorstep sell pai behalf resel vat due price product resel sell custom provid entir turnov firm obtain doorstep sale resel work account price list set sell price charg public firm product drawn advanc adher derog appli sole case firm sell product direct resel turn sell direct final consum firm fulfil condit duli authoris tax administr pai treasuri amount vat due pre establish retail sell price resel concern longer requir pai tax sale benefit deduct arrang constitut derog articl sixth direct wholesal deem liabl tax good sold end consum resel wholesal requir fulfil oblig tax return tax invoic payment tax respect good resel sell final consum derog articl resel exempt oblig respect good suppli final consum arrang authoris earlier council decis ec januari applic januari decemb commiss consid derog simplif measur fulfil condit set articl sixth direct derog authoris decemb derog alter amount vat collect stage final consumpt neg effect european commun resourc obtain ad tax adopt decis articl portug authoris appli decemb special measur taxat doorstep sale provis derog sixth direct eec busi total turnov deriv doorstep sale made resel act account request administr authoris appli provis articl condit product sold firm contain pre establish price list applic final consumpt stage firm sell product direct resel turn sell direct final consum articl derog articl sixth direct eec firm authoris appli special measur liabl tax payabl good suppli resel final consum articl resel suppli busi authoris appli special measur exempt oblig laid articl sixth direct eec good suppli final consum articl decis address portug luxembourg octob council presid zalm oj direct amend direct ec oj oj