Most agreements are valid orally: Slovak law generally allows freedom of form. However, writing may be required by law, for example for property transfers, or by the parties themselves. If the prescribed written form is missing, the agreement is invalid. Amendments require a distinction between civil and commercial law: in a commercial relationship, merely signing the agreement in writing does not mean that every amendment must also be in writing. In practice, writing is recommended even where the law does not require it, for evidence and certainty.
Is an oral agreement valid?
Slovak private law starts from the principle that a legal act needs no special form to be valid. An agreement can be made orally, through conduct or even by a handshake. Invalidity for lack of form arises only if the act was not made in the form required by law or agreed by the parties (Section 40(1) of the Civil Code). In other words, if neither legislation nor agreement requires writing, an oral agreement is fully valid and binding.
When does the law require writing?
For some agreements, writing is a condition of validity. This typically applies to property transfers and other agreements where law or the parties require it (Section 46(1)). In a property transfer, both parties’ expressions of intent must also appear in the same document (Section 46(2)). The law also requires writing for contractual penalties and agreements to enter into a future agreement, for example. Written form is preserved where an act is performed electronically using means that record its contents and identify the person acting (Section 40(4)).
Can a written agreement be amended orally?
Under civil law, an agreement concluded in writing may only be amended or cancelled in writing (Section 40(2) of the Civil Code). Commercial agreements are subject to the specific rule in Section 272(2) of the Commercial Code: where a written agreement states that it may be amended or cancelled only in writing, that form must be observed. Merely concluding the original commercial agreement in writing does not automatically prohibit an oral amendment. Any specific statutory form requirements applicable to the particular legal act remain decisive.
Why put it in writing even when you do not have to?
We recommend writing even where it is not legally required. A written agreement proves what was agreed and protects against one person’s word being set against another’s. We draft and review documents tailored to your transaction: bespoke commercial agreements, works contracts and reviews of existing agreements before signing.
This answer provides general information on the law as at 10 September 2026. It does not constitute legal services or replace an assessment of an individual case. The details of your situation may differ. Book a consultation to discuss them.
