Is: The balance on the clearing account should be zero and accounts for the timing difference between invoice receipt and matching.
Should be: Split the sentence after /zero/. Replace /and/ with "It".
Reason: "He should take care of himself and goes to bed in the evening" does not sound like good English to me although I cannot come up with a rule that says it is wrong either.
And there is still something wrong with the meaning. If the intended meaning is that a nonzero balance indicates a timing difference, that fact should rather be expressed verbatim than left to the reader's ingenuity. On the other hand, if a nonzero balance is an abnormal situation that indicates an accounting error, the balance cannot account for anything because it is always zero (hopefully).