Regarding tolerances

Hi,

User is posting a transaction in FB05 and writing off the whole amount of the open line item using the posting with clearing option and he says that A/R tolerances in SAP system are not working.

My question is when should be the option posting with clearing should be used...what for this is used.

I have tested the scenarios in development and the tolerances are working fine when partial payment is received.I was able to write off amount with in tolerances only.

Will the tolerances be applicable when we writeoff the whole amount without receiving the payment.

Please clarify

Regards

Aravind