13 June 2014
when you have to debit another party in your books, you issue a debit note. for eg: sales purchase return. In a purchase return, you will debit your creditor, so you issue a debit nore.
on the other hand credit note is issued when you want to credit someone in your books.
For eg, if you are making sales return, you will have to credit your debtor, so you issue a credit note.
please note that what is a credit note in your books is a debit note in the other party's books and vice-versa.
16 June 2014
Debit note / credit note are known as adjustment documents too. if there is any diff arose in amount previously charged, you can adjust it by debit/credit Note