Advance Tax Collection

Advance Tax Collection

Hi,
 
I am running into a problem that probably you might be able to help me out here. The issue is when customer pay us against our invoice they deduct 1% advance and submitted to FBR (Faderal Board of Revenue) just like IRS in America. Once we get paid from the customer then we have to pay the remaining tax amount to FBR minus 1% that the customer collected from us in advance.
 
Now I have setup my Zoho books to deduct the 1% advanced tax from the total invoice but my Tax payable does not minus the 1% from the total Tax payable balance. How can I minus the 1% from the Tax Payable balance. Because after I pay the suppose amount to FBR my Zoho books show 1% amount in the Tax Payable balance and it just stay there.
 
Please I need help to smooth my bookkeeping process.
 
Thanks,
 
Salman