2 Points
Joined December 2016
As you want to know how to do it in tally.For making sales Invoice.
Go to Gateway of Tally> Accounting Voucher> F8 Sales.
As you are providing service, Click on Accounting Invoice button or Use shortcut Key Alt+I .
Enter party name, Under particulars select the service expense ledger like professional fees. enter amount and save.
Here is how to do sales entry invoice in tally erp 9
When clients pays you money.
You have to enter it in receipt voucher.
Go to Gateway of Tally> Accounting Voucher> F6 Receipt Voucher.
If client is paying through cash ,select cash under field 'Account' If through cheque or online payment, select the bank name in which you are going to deposit.
under particulars : Select the clients name. and save the voucher. Please refer below link for detailed tutorial
How to enter receipt voucher
Hope this helps.