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Regular expression for validating US telephone numbers with OPTIONAL area code. Matches various permutations of formatting characters (parenthesis, space, dash). Parses the telephone number area code, prefix, and suffix to named groups to facilitate program manipulation. Area code is optional and can optionally be enclosed in parentheses. Rejects area codes that begin with 0 or 1 and prefixes that begin with 0. Rejects all telephone numbers that do not match on exactly 7 digits, or on exactly 10 digits with the optional area code, not counting the formatting characters.

Regular expression for validating US telephone numbers with OPTIONAL area code, and OPTIONAL extension. Matches various permutations of formatting characters (parenthesis, space, dash). Parses the telephone number area code, prefix, suffix, and extension to named groups to facilitate program manipulation. Area code is optional and can optionally be enclosed in parentheses. Rejects area codes that begin with 0 or 1 and prefixes that begin with 0. Extension is optional and can be optionally preceded by a space and/or "x" or "X", and matches on 2 to 4 digits. Rejects all telephone numbers that do not match on exactly 7 digits, or on exactly 10 digits with the optional area code, not counting the extension or the formatting characters.

Example of a regular expression that can be used to parse a comma delimited string into constituent, named sub-strings. Add or remove regex subfield definitions (?<field1>[^,]+) and corresponding delimiting characters in the regular expression as necessary to accommodate the string and subfields you intend to parse. Optionally, rename the subfield names in the regular expression to more meaningful names if you are using the parsed sub-strings in a program. Replace all occurrences of the comma in the regular expression with any required alternative delimiting character. As long as the delimiting character used does not occur naturally in any of the sub-strings, you should be good-to-go. NOTE: To change the delimiter character you must replace all occurrences of the comma in the current regex (of which there are 5) with the new delimiter character. e.g. (?<field1>[^;]+); changes the delimiter character to a semi-colon for the first field.

Updated on 3/4/2004 per feedback to additionally exclude SSNs that begin with 666 which, as reported, are also not valid. Regular expression for validating US Social Security Numbers. Accepts optional hyphens or spaces as formatting characters. Parses the three subfields of the SSN into three named sub-strings (SSN1, SSN2, and SSN3) to facilitate program use. Rejects matches on all zeros for any individual subfield of the Social Security Number. Matches only on those SSNs that fall within the range of numbers currently allocated by the Social Security Administration.

Updated on 7 Jun 2005 -- Matches major credit cards including: Visa (length 16, prefix 4); Mastercard (length 16, prefix 51-55); Diners Club/Carte Blanche (length 14, prefix 36, 38, or 300-305); Discover (length 16, prefix 6011); American Express (length 15, prefix 34 or 37). Saves the card type as a named group to facilitate further validation against a "card type" checkbox in a program. All 16 digit formats are grouped 4-4-4-4 with an optional hyphen or space between each group of 4 digits. The American Express format is grouped 4-6-5 with an optional hyphen or space between each group of digits. Formatting characters must be consistant, i.e. if two groups are separated by a hyphen, all groups must be separated by a hyphen for a match to occur.

Regular expression for validating a decimal IP address. Matches 4 groups of from 1 to 3 digits, where each group of digits ranges from 0 to 255 in value. Groups of digits must be separated by a single period (.) with no other formatting characters present. Uses conditional regex with lookahead syntax to prevent a match on a period following the final group of digits.

Regular expression for validating a US currency string field. Matches an unlimited number of digits to the left of an optional decimal point. Digits to the left of the decimal point can optionally be formatted with commas, in standard US currency format. If the decimal point is present, it must be followed by exactly two digits to the right. Matches an optional preceding dollar sign. Uses regex lookahead to preclude leading zeros and to match the optional formatting comma.

Regular expression for validating a person's full name. Matches on two general formats: 1) first second third last (where first, second, and third names are optional and all present are separated by a space); 2) last, first second third (where second and third are optional, last is followed immediately by a comma and a space, and second, and third, if present, are separated by a space from each other and from first). First corresponds to surname and last corresponds to family name. Each name part is captured to a named group to facilitate program manipulation. Each name part must begin with an uppercase letter, followed by zero or more lowercase letters, except for the last name. Last name must begin with an uppercase letter, followed by one or more lowercase letters, but will match exceptions formatted like the following: McD..., MacD..., O'R... Only format is validated, not spelling. NOTE: This regular expression uses positive and negative regex lookahead to determine the general format of the name, i.e. the presence or the absence of the comma determines the general format that will match. Furthermore, this initial version is not designed to accommodate titles and things like "3rd".

Validate US zip codes. Matches all zip codes of exactly 5 digits except 00000. Optionally, matches zip5+zip4 where zip5 is exactly 5 digits, zip4 is exactly 4 digits, and zip5 and zip4 are, optionally, separated by a single space or hyphen. Captures zip5 and zip4 to named groups to facilitate program manipulation.

Validates dates from 1/1/0001 to 12/31/9999. Month and day can be preceded by a zero to a max of two digits; however, year must be four digits exactly. This regex was developed in a .NET environment and uses conditional lookahead syntax, so your regex engine must support same. Month, day, and year are captured to groups named "month", "day", and "year" for additional processing if desired.

Validates the format of a US mailing address that includes a maximum of three lines. line1 (cannot be whitespace) line2 (optional; if present, cannot be whitespace) city, ST 00000-0000 (hyphen and last four digits of zip are optional) Captures line1, line2 (if present), city, state, and zip to groups similarly named for further processing.

Validates US state abbreviations used by the Post Office.