Article 390 of Commercial Code

1 - If the items of the current account include monetary debts denominated in different currencies or dissimilar things, the parties may agree to enter them in the account, provided that they are entered in Law Index 1308 Home Page Commercial Law Decree-Law No. 68 of 1980 Promulgating the Commercial Law separate sections in which similarity among the payments they contain is observed, and that the parties expressly declare that the account shall retain its unity notwithstanding the multiplicity of its sections. 2 - The balances of those sections must be convertible so that, at the time specified by the parties or, at the latest, upon closure of the account, a set-off may be effected between them to derive a single balance.