This is an eternal question and the most common dilemma for young workers encountering the labor market for the first time. Although net is often discussed in everyday speech, in modern business, the only fair legal norm is - absolutely GROSS negotiation.
The Labor Law usually mandates defining the salary exclusively in the corresponding GROSS amount in the Employment Contract itself. Although you can informally agree on a net amount, the law only recognizes the Gross.
A worker often wants to know the exact amount available to them. However, agreeing on a fixed net hides significant traps that work in favor of the employer.
If the state reduces income tax: - If you have an agreed gross, your net salary increases. - If you have an agreed fixed net, the difference remains with the employer as savings, and your salary stays the same.
Children and dependent family members increase your tax-free part of the salary. With a gross contract, this directly increases your net. With a fixed net, the employer pays less tax to the state, and pays you the same agreed net.
Poor employers may agree on a low gross and pay the difference to the agreed net through tax-free allowances (meal allowance, transport). This reduces the base for your future pension and your creditworthiness at the bank.
Demanding clearly defined gross negotiation protects you and your pension. Negotiating exclusively the gross amount ensures that every tax deduction or legal relief ends up in your pocket.