A DBA ensures that a subject is not subject to unjustified taxation, both in South Africa and in the country concerned that is treated in a given DBA. It is therefore a defence of double taxation and defines different requirements that a taxpayer must meet in order to understand where that tax subject is as a taxable resident. For two reasons, the situation becomes more problematic when it comes to adopting later versions of the comment. Since subsequent comments may be based on different formulations in the articles of the OECD model, i.e. on articles that both states have never actually signed, the courts may not be willing to follow the comments, as the corresponding articles have never been approved by the GOVERNMENT of that state. Second, the courts expect the LTCV to be more complicated because states have not negotiated further comments bilaterally, making it difficult to argue that there is a subsequent agreement. 3. If the context does not require otherwise, but the provisions of domestic law are applied outside the scope of the taxes covered by the treaty, general rules of interpretation should apply. Article 3, paragraph 2 of the OECD Model Convention provides that, for the purposes of the convention, any concept that is not defined in it has the meaning it has at that time under that state`s law, unless the context requires otherwise. Article 3, paragraph 2, of the tax treaty therefore constitutes a bridge to national legislation, but with reference to the context.
DBAs are bilateral agreements between two states. It is therefore essential that those who apply the agreements follow the relevant guidelines of national courts when interpreting conflicting clauses. As a general rule, the preamble to a DBA recites its purpose as a kind of « prevention of double taxation and the prevention of tax evasion. »  In addition, it is important to recognize that a DBA is an international agreement that includes the domestic laws of several jurisdictions that may have different interpretations of the same provision. In particular, some states – the so-called monistic states – treat the DBA as superior to previous or post-state national legislation, while others follow the so-called dualist model and only recognize a status greater than a DBA when the national legislator has approved the instrument.  The main objective and purpose of a tax treaty in the preamble is to avoid international double taxation in order to facilitate international trade and to distribute tax duties among States Parties. The preamble in the 2019 OECD model convention has been expanded to exclude the creation of opportunities for non-taxation or reduction of tax evasion or evasion from the subject of a contract.