Customer Deductions in payments

Customer Deductions in payments

Hi

its common for my customer to deduct some amount from my invoice raised on them
So i would like to know  how to record it at customer deductions.Please note this is not tax.Tax is seperate deuctions which is made by few customers

Please advise me on

1.How to record deductions - these deductions are not receivable to me and need to write off.
2.How to record tds
3.How to apply single payment received in bank for more than one customer.(This is very common for me as i do business for a MNC with different branches yet the payment is centralized.Its getting difficult for me record it and i doing it manually as two different bank transactions, though the actual entries in real bank statement is single)