Business accounting:
the complete business administration.
Settlement of all taxes:
Sales Tax, Income Tax, Wage Tax,
Tax returns, any appeals,
communication with the tax authority.
Social Security, pensions.
Returning Income Tax,
applying for allowances,
and so on.
Pension deferral or early retirement;
income tax return M-form;
tax treaty between the country in which you reside and the Netherlands;
taxation in the Netherlands when there is no tax treaty involved.