[GNC] Set up GnuCash to track monthly net income considering taxes and pension fund contributions

[Simone Gaiarin]

Hi all,
I need help in setting up GnuCash to achieve the following goal:
- Track my monthly net income (after taxes and pension fund contribution)

Situation:
I give a service that I invoice per hour and the cost paid by the customer
consists of the following components:

x: Cash payment = y + p1
y: Service gross cost
p1: 1st pension fund contribution = 0,02 * y

On y I have to pay also:
t1: tax I have to pay = 0,05 * y
p2: 2nd pension fund contribution = 0,10 * (y - t1)

Accounts:

- Income

- Bank Account

- Tax
- Pension fund

Given that I pay out of my bank account the taxes twice a year and the
contribution to the pension fund twice a year, the 'Income chart' report
does not give me a clear view of my net income over the month.

I tried to set up a tax table where I used some equivalent coefficients in
order to automatically assign t1 to Tax account and p1, p2 to the Pension
fund account (rather difficult given that here the tax and pension fund are
computed in cascade), but I wonder if this is the correct strategy (the
Pension fund account goes negative instead of positive for example).

What is the correct way to proceed in order to obtain a monthly net income
chart considering the taxes and pension fund contribution percent over each
customer payment?

Thanks