BER is a three letter abbreviation that can refer to the following:

• Basic Encoding Rules are a set of rules for encoding data that is described using the ASN.1 standard, for the purpose of transmission to a different computer system.
• Berber language (other) (ISO 639 alpha-3, ber)
• Bit Error Ratio is the ratio between the number of incorrect bits transmitted to the total number of bits ( E.800)
• Borohydride Exchange Resin a common catalyst