What Is Stamp Duty?
Definition
Stamp Duty: A tax on documents such as contracts, leases, guarantees, decisions and payslips. It is usually a small share, per mille, of the amount the document shows, often capped per document.
Stamp duty is a tax on documents such as contracts, leases, guarantees, decisions and payslips. Most documents pay a small share, given per mille, of the amount they show; the rate depends on the document type. Many countries cap the duty on one document. On a payslip it is one of the deductions from the gross wage.
Where it appears in the formulas
stamp duty = min(amount × per mille rate; maximum per document). The stamp duty calculator picks the rate and the maximum by the document’s year. The salary, severance and notice pay calculators charge it on wages.
In Türkiye
Stamp Duty Law no. 488 sets the duty; most documents pay a per mille share of the amount they show. In 2026 contracts pay 9.48‰ and leases 1.89‰. The duty on one document cannot exceed that year’s maximum per document: 29,115,961.10 TRY in 2026 (General Communiqué on Stamp Duty no. 71). The salary, severance and notice pay calculators charge 7.59‰ on wages.