Cumulative discount received entry posting.

Hi all,

The situation is, our company purchases raw material from a particular vendor. In case the purchases exceed a particular limit (amount) in a year the supplier gives a lump sum discount on all the previous purchases done in the year. this discount amount is received as a cheque which amounts to a few lakh rupees. now the client wants to book this amount as discount received. how do i proceed with the posting of such transaction?? would it be appropriate if i remove the post automatically checkbox for discount received GL account an directly post a Journal entry to the account or is there any other way?? and if we do so wouldn't it be questioned during financial audit.?? Please suggest.

Thanks.

Pritesh Tatar.