Stamp duties are taxes paid to the Federal or State governments on Land Instruments such as Conveyances on Sales, Agreements and Contracts documents.

Every State and the Federal Capital Territory (FCT) has a Stamp Duties Law, which establishes the Stamp Duties Office and makes provisions for the process of stamping documents. The duty on land controlled by the State is paid to the State Internal Revenue Board (e.g Lagos LIRS) and that under Federal is paid to the Federal Inland Revenue Service (FIRS). Section 4 (1) Stamp Duties Act, Cap. S8 Laws of the Federation of Nigeria, 2004 states that the Federal Government is the only competent authority to impose, charge and collect duties on instruments specified in the schedule to the Stamp Duties Act where such instruments relate to matters executed between a company and an individual. Stamp duties is a matter in the Exclusive Legislative List of the 1999 Constitution. Which means that, the legal basis of stamp duties is owned by the Federal Government. However, the State governments are permitted to collect duties where the party executing the instrument is an individual.

Stamping of documents should be within 30 days of the execution of the document though it may be stamped out of time, but would attract penalty. Stamp duty statues are tax laws, meant to generate revenue for government. The amount payable is either a flat rate or ad valorem that is according to the value of the transaction, for instance, an Assignment. The law permits the use of post office stamp, which must however be cancelled to avoid loss of revenue on the part of the government. The effect of an unstamped document is that the document cannot be tendered in court as an evidence, and it cannot be accepted for registration.