Vendor Mobilization Advance

Dear Experts,

        In Work Order I have mentioned 15% Mobilization Advance to vendor out of which 10% of advance is recoverable and 5% should be non recoverable.

While doing invoice (MIRO) 10 % advance can be recovered/settled. How to handle the non recoverable advance i.e. 5% in SAP.

Please suggest.

Regards

Chinmaya