There is no clear legal regulation on which finger should be used to press fingerprints. In practice, the index finger of the right hand is generally used to press fingerprints.

Pressing fingerprints is a traditional way of signing contracts in China since ancient times. Because in the 1950s, especially before the end of the Qing Dynasty, the proportion of Chinese people with illiteracy was very high, and most people could not read or write. Therefore, when signing relevant contracts or other legal documents, it was often necessary to find literate and written tribesmen to draft the legal documents, and then leave it to the parties. Draw a sign (draw a word or figure according to the party's own understanding), and add the party's fingerprint to confirm the signing of the legal document.

In fact, fingerprint identification and comparison in ancient times were difficult and very inaccurate. However, people at that time were introverted and had faith (perhaps they were superstitious and feared God’s punishment), and related operations often existed Many witnesses, therefore, generally do not dare to deny the documents on which they have their thumbprints. In order to ensure the authenticity of this fingerprint and facilitate comparison and verification, the thumb of the right hand is generally used to press the fingerprint;

The initial motivation comes from the fact that the right hand is the main functional hand (compared to the left hand), and secondly, the right hand is larger. The thumb accounts for about 40% of the total hand function (in terms of disability assessment, if the thumb of the right hand is missing, it is regarded as a loss of about 40% of the function of the right hand), and it can be called the king of fingers. Later, the right thumb was generally used for fingerprints, which provided the best guarantee for finding comparison samples (previous fingerprints) in case of future disputes. This has increasingly strengthened the operation mode of signing legal documents with the right thumb.

The court's interpretation, the Contract Law Interpretation (2009), etc., only inherit and continue this operation, but they are not the source of the fingerprints. There is no law that states which finger must be used to make a seal; the thumb of the right hand is the first choice.

Extended information

As for pressing fingerprints, modern society generally does not use it alone, unless the person concerned cannot write. The advantage of pressing fingerprints is to clarify the identity.

This can be done "without a doubt", because each person's fingerprint is absolutely unique, but it requires high technology to identify, so its flaws cannot be ignored, and fingerprinting does not easily reflect personal freedom. Will, like torture in the old society, the last step in surrendering is for the person's fingerprints to be "pressed" on the crime.

The most prudent: use a combination of signature and fingerprinting

Signing, sealing, and fingerprinting are related to everyone’s vital interests. You should be cautious before writing, if there is any situation such as being forced. , evidence should be preserved. At the same time, you should read the contents of the contract agreement clearly, and never sign, seal, or fingerprint casually just because of feelings.