實質課稅原則為租稅法之重要原則，本論文經由以下個案，探討稅捐稽徵機關以往對實質課稅原則之運用。 一、稅務稽徵機關以實質課稅為由否准四大金融業以債券前手息扣繳稅款抵繳其營利事業所得稅，何謂實質課稅原則?租稅法律主義與實質課稅原則應如何調和？ 二、從認購(售)權證成本之發生成因、課稅爭議之歷史沿革、並從徵納雙方對所得稅法之見解，探討實質課稅原則與租稅法律主義之競合。 三、複委託交易個案之探討－此處探討現行涉外所得課稅規定是否有不妥之處。 四、未來即將上市之海外來台第一上市股票、跨境ETF與新上市之指數型權證可能稅賦之探討－由相類似國內金融商品之課稅規定分析，探討稅負上是否具有一致性。 本研究建議： 一、稅捐稽徵機關應履行探究經濟實質之義務，方可主張實質課稅。 二、給付國外勞務報酬是否課稅應以實質認定，建議應定性為所得稅法第8條第9款之所得，並就在台固定營業場所或營業代理人之情形實質認定，以兼顧課稅要件明確與實質課稅精神。 三、應明文闡述支付國外券商複委託交易手續費屬營業稅課稅範圍之判定標準，以符合租稅法律主義之規範。 四、金融商品之課稅架構，應謹守租稅中立原則，保持一致性，避免對特定金融商品做特殊解釋。 / This research explored four cases in order to find out how the tax authority applies “substance versus form doctrine” in the some disputes. 1.The right to claim tax credit for withholding tax derived from bond interest had been long disputed. Can we say the tax authority’s view is "substance over form"? Did the amended Income Tax Act on 2007 solve the said dispute? 2.On the contrary, the tax authority isn’t in the view of "substance over form" for the tax deduction of hedge cost by warrant issuer. This study summary several Administrative Court adjudications to explore each party’s view. Can "substance over form" govern” “taxation by law“? 3.Securities firms conducting the business of accepting orders to trade foreign securities involve VAT and source income issues. This study addresses why the tax disputes arise and how to solve them. 4.This study also analyzes investors’ possible tax liability of coming List Securities by Foreign Issuers, Offshore ETF and newly Index Warrant. The suggestions in the above cases are as follows. 1.The tax authority should fulfill its duty to find out the economical substance then has a right disallow tax evasion. 2.The principles for determining Taiwan source income can adopt PE and business agent concept to mitigate the conflict between tax payers and tax authority. 3.The tax authority should interpret the criteria why offshore securities firms’ services should impose VAT. 4.The tax authority should be in the view of "substance over form" and maintain consistency while issuing tax ruling.

South Africa has expressed its desire to be the gateway for investment into Africa. With its residence-based tax system which taxes the worldwide income of its tax residents, South African companies will be open to double taxation where the investee country claims jurisdiction to tax income generated from within its borders. In addition, other provisions in the South African tax legislation increase the possibility of double taxation by including the income of foreign subsidiaries. Two such examples are the definition of a tax resident, which includes foreign subsidiaries that are effectively managed by their holding companies in South Africa, and the anti-avoidance measures, such as the controlled foreign company provisions, which impute the income of a foreign subsidiary to the South African investment company. Many South African companies have chosen to route their investments in African countries through foreign subsidiaries. Besides having a more investor-friendly tax regime, these countries offer more favourable relief from double taxation, both unilaterally and by means of their network of tax treaties. South Africa has identified some of its shortcomings. It has introduced concessionary tax provisions for locally based headquarter companies that invest abroad. It recognises the high cost of doing business in Africa due to the fact that many African countries impose withholding taxes on several types of income even though they may not be from a local source. Therefore, South Africa is granting tax rebates for foreign withholding taxes paid on service fees charged to foreign entities despite the income being derived from a South African source. Both these measures reduce double taxation but, are they sufficient to encourage direct investment from South Africa into other African countries? This study seeks to evaluate the effectiveness of the South African double taxation relief provisions by using a case study of a South African company that has investments in several African countries. It compares the application of the double taxation relief provisions of South Africa, another African country and a non-African country to the case study. It analyses the outcomes and assesses the effectiveness of South Africa’s current legislation for unilateral tax relief and its tax treaties in minimising double taxation. Finally, it makes some recommendations on possible improvements to the legislation in order to achieve the stated goal of being the financial hub for investment into Africa AFRIKAANS : Suid Afrika het aangedui dat dit die poort vir belegging na Afrika wil wees. Die heffing van belasting op die wêreldwye inkomste van belastingpligtige inwoners stel Suid-Afrikaanse maatskappye egter bloot aan dubbelbelasting indien die land waarin beleggings gemaak word ook aanspraak maak op die reg om inkomste wat in daardie land verdien is, te belas. Sekere bepalings in die Suid-Afrikaanse belastingwetgewing stel belastingbetalers verder bloot aan dubbelbelasting indien die inkomste van buitelandse filiale ook by die inkomste van inwoners ingesluit moet word. Twee sulke voorbeelde sluit die definisie van belastingpligtige inwoner ingevolge waarvan buitelandse filiale wat effektiewelik deur hulle houermaatskappy in Suid-Afrika bestuur word en sekere teenvermydingsmaatstawwe, soos byvoorbeeld die beheerde buitelandse maatskappy bepalings ingevolge waarvan die inkomste van ʼn buitelandse filiaal aan ʼn Suid-Afrikaanse beleggingsmaatskappy toegeskryf word, in. Daar is heelwat Suid-Afrikaanse maatskappye wat verkies om hulle beleggings in Afrika deur middel van filiale wat in ander lande geregistreer is, te hou. Hierdie gekose lande het nie net gunstige belasting instellings bewinde nie maar bied ook meer voordelige verligting van dubbelbelasting, beide eensydig en deur middel van hulle netwerk van belastingooreenkomste, aan. Suid-Afrika het sy tekortkominge geidentifiseer. Voordelige belastingbepalings is geskep vir plaaslike hoofkantoor maatskappye wat beleggings in die buiteland hou. Erkenning is gegee aan die hoë koste om besigheid in Afrika te doen as gevolg van die feit dat menige Afrika-lande belasting op verskeie tipe inkomste weerhou selfs as die oorsprong van die inkomste nie vanuit daardie lande kom nie. Suid-Afrika is gewillig om belastingkortings vir die buitelandse belasting so weerhou toe te staan ten spyte daarvan dat die oorsprong van die inkomste in Suid-Afrika is. Beide die maatstawwe is gemik op tot die vermindering van dubbelbelasting, maar is dit voldoende om direkte beleggings vanaf Suid-Afrika in ander Afrika-lande aan te moedig? Die doelwit van hierdie studie is om te bepaal hoe effektief die Suid-Afrikaanse bepalings wat gemik is om dubbelbelasting te verhoed deur middel van ‘n gevallestudie van ʼn Suid-Afrikaanse maatskappy wat meervoudige beleggings in verskeie Afrika-lande het. Die studie vergelyk die toepassing van die vermindering van dubbelbelastingbepalings van Suid-Afrika, ʼn ander Afrika-land en ʼn nie-Afrika-land. Die resultate word geanaliseer en die effektiwiteit van die huidige wetgewing vir eensydige verligting van dubbelbelasting en die huidige belastingooreenkomste om dubbelbelasting te verminder, word beraam. Ten slotte, die studie beoog ook om aanbevelings wat dalk die wetgewing kan verbeter ten einde die gewensde doelwit om Suid Afrika die finansiële poort vir beleggings in Afrika te bereik, te maak. / Dissertation (MCom)--University of Pretoria, 2012. / Taxation / unrestricted