it's not wrong, but kontera is the very specific act of assigning a transaction to the proper account, with none of the general meaning of classify. Kontera sort of implies the act and transaction, the "commit".
Yes, I probably explained it a little too simplistic. Describing it as the commit is quite accurate I think. In my program I came up with the verb "book" for this, as book a transaction, but I have no idea if it is correct in the English-speaking world.