In information theory and coding, an error-detecting code is a code in which each data signal conforms to specific rules of construction so that departures from this construction in the received signal can generally be automatically detected. This concept is applied in telecommunication. It is less powerful but very similar to an Error-correcting code.

A notable error detecting (and error correcting) code is the Hamming code.

Note 1: Error-detecting codes require more signal elements than are necessary to convey the basic information.

Note 2: The two main classes of error-detecting codes are block codes and convolutional codes.

See also Error-correcting code - Parity