Magnetic stripe card

CR80 ISO standard card, 2-3 stripes. Magnetic stripes are used in credit cards, cost control cards, copy machine cards and so on.

The stripe on the back of a magcard is a magnetic stripe, often called a magstripe. The magstripe is located 0.223 inches (0.56642 centimeters) from the edge of the card, and is 0.375 inches (0.9525 centimeters) wide. It is made up of tiny iron-based magnetic particles in a plastic-like film. Magstripes come in two varieties: high-coercivity and low-coercivity. High-coercivity magstripes are harder to erase, and therefore are appropriate for cards that are frequently used or which need to have a long life. Low-coercivity magstripes require a lower amount of magnetic energy to record, and hence the card writers are much cheaper than machines which are capable of recording high-coercivity magstripes. A card reader can read either type of magstripe, but a high-coercivity card writer may only write high-coercivity cards, while a low-coercivity card writer may only write low-coercivity cards.

The magnetic stripe contains three tracks, each 0.110 inches wide. Tracks one and three are typically recorded at 210 bits per inch, while track two typically has a recording density of 75 bits per inch. Each track can either contain 7-bit alphanumeric characters, or 5-bit numeric characters.

Two common specifications of the data that can be recorded on the magstripe is ISO 7813, which was originally intended for financial cards, and the American Association of Motor Vehicle Administrators (AAMVA) specification, which specifies the encoding used on drivers licenses.

Financial cards

The information on track one on financical cards is contained in two formats: A, which is reserved for proprietary use of the card issuer, and B, which includes the following:

• Start sentinel - one character (generally '%')
• Format code="B" - one character (alpha only)
• Primary account number - up to 19 characters
• Field Separator - one character (generally '^')
• Name - two to 26 characters
• Field Separator - one character (generally '^')
• Expiration date - four characters
• Service code - three characters
• Discretionary data - may include Pin Verification Key Indicator (PVKI, 1 character), Pin Verification Value (PVV, 4 characters), Card Verification Value or Card Verification Code (CVV or CVK, 3 characters)
• End sentinel - one character (generally '?')
• Longitudinal redundancy check (LRC) - one character

LRC is a form of computed check character.

The format for track two, developed by the banking industry (ABA), is as follows:

• Start sentinel - one character (generally ';')
• Primary account number - up to 19 chars
• Separator - one char (generally '=')
• Expiration date - four characters
• Service code - three characters
• Expiration date - four characters
• Discretionary data - as in track one
• End sentinel - one character (generally '?')
• LRC - one character

The format for track three, as specified in ISO 4909 is as follows:

• Start sentinel - one character (generally ';')
• Format code="B" - one character (alpha only)
• Primary account number - up to 19 characters
• Field Separator - one character (generally '=')
• Country code optional, 3 characters
• Currency code 3 characters
• Currecy Exponent 1 characters
• Amount Authorized per Cycle 4 characters
• Amount remaining this cycle 4 characters
• cycle begin (validity date) 4 characters
• cycle length 2 characters
• retry count 1 character
• Pin control paramters (optional) 6 characters
• Interchange controls 1 characters
• PAN Service restriction 2 characters
• SAN-1 Service Restriction 2 characters
• SAN-2 Service Restriction 2 characters
• Expiration date (optional) 4 characters
• Card Sequence number 1 character
• Card Security Number optional, 9 characters
• First subsidary account number optional
• Secondary subsidary account number optional
• Relay Marker 1 character
• Cryptographic Check Digits optional, 6 charactrers
• Descretionary Data
• End sentinel - one character (generally '?')
• Longitudinal redundancy check (LRC) - one character

Driver's Licenses

The data stored on magnetic stripes on driver's licenses is specified by the American Assosiation of Motor Vehicle Administrators (AAMVA).

The following data is stored on track 1:

• State or Province
• City
• Name
• Address

The following data is stored on track 2:

• ISO Issuer Identifier Number (IIN)
• Drivers License / Identification Number
• Field Separator - generally '='
• Expiration Date
• Birth date
• DL/ID# overflow

The following data is stored on track 3:

• Template V#
• Security V#
• Postal Code
• Class
• Restrictions
• Endorsements
• Sex
• Height
• Weight
• Hair Color
• Eye Color
• ID#
• Reserved Space
• Error Correction
• Security

See also: ISO 7810