Trade debt is a very important source of financing with some significant factors to induce more or less (including the substitution effect) trade credit extending: long-term financing, size, return on assets, return on equity and fixed assets, in one hand; short-term financing (substitution effect), growth and return on sales. Interacted country-return interacted variables are also responsible for a more discipline on trade debt behaviour and management because of relevant and significant reducing trade debt factors. But, much more important is to reveal what different types of return may better and deeply influence trade debt extended by creditors. This is an innovative research to improve trade debt management conditions and to suggest replacing firm’s fixed assets by assets structure flexibility, in a short-term financing flexibility environment. The results show that: (1) Interacted country-return explanatory variables have more relevant effects on trade debt, than internal profitability; (2) Each assets structure and short-term financing flexibility devaluate long-term debt as a financing substitute or complement of trade credit obtained from suppliers; (3) While assets structure flexibility imposes more discipline, short-term financing flexibility reinforces trade credit obtained from suppliers and (4) Both assets structure and short-term financing flexibilities transform long-term financing on a second level substitution effect of trade debt.