In modern society, standard contract terms play very important role in everyday transactions. The interest of the clients can be neglected by the unfair standard contract terms. Every person has bank account. Bank trade plays significant role in everyday life of the people. Korean people want to have their own houses. Therefore they borrow money on their house. This is so called mortage loans. Subprime mortage was a cause of the global financial crisis in the year of 2007, 2008. It happens very often that people confront problems with the use of inadequate standard contract terms. This study concentrates on analysing justification criteria of deviation clauses from dispositive law. The contents of standard contract terms about bank business should be valid in regard of korean unfair contract terms act and jurisdiction. There were some discussions about the problem, who should bear the fee for getting mortage in korea. The old standard contract terms about bank business allows the selection of the parties in this point. But the korean fair trade commission has revised the standard contract terms about bank business. It has also enforced the new clauses to all banks. The bank association sued the fair trade commission. The seoul high court accepted the claim of the bank association. But the supreme court has broken off the decision and refer the case back to seoul high court. The seoul high court has interpreted according to the direction of supreme court. The attitude of the korean court toward clauses about bank business, in short, has problems. The older clauses are adequate in regard of the interest division of the parties. On the other hand, standard contract terms can deviate from dispositive law. But in that case the rule of minimum deviation should be applied. The dispositive law has set a standard for the people. Because of the principle of private autonomy the deviation from the dispositive law should be allowed. But we should find out the right criterium of the acceptance of the clauses according to the standard contract terms law and principles. The author has in this article studied the justification- criteria of deviation clauses from dispositive law. By the analysis, he has seen especially the german literature.