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Matches the first part of a UK Postcode (known as a postcode district). Case insensitive. Doesnt match: GIR # the postcode for the formerly Post Office-owned Girobank is GIR 0AA. SAN # the postcode for correctly addressed letters to Father Christmas is SAN TA1

This regex only matches clean domain names. No path after. Ends in a forward slash. Starts with http://www. It is pretty slack on the TLD requiring a 2 or 3 letter ending. This part could be tightened up if you wanted to be restrict it to specific TLDs.

Allows dashes or spaces to separate.

Allows dashes or spaces to separate.

Allows dashes or spaces to separate.

Allows dashes or spaces to separate.

Allows dashes or spaces to separate.

Validates the format of a UK bank sort code.

UK Bank account numbers are 8 digits. One bank uses 7 digits so in the validation error message you should instruct the user to prefix with a zero of their code is too short. If you want to allow the 7 digit codes as well use this regex: http://regexlib.com/REDetails.aspx?regexp_id=2707

UK Bank Account. One bank account issues 7 digit bank codes and you should prefix a 0 yourself after input. If you want strict validation of 8 characters use this regex: http://regexlib.com/REDetails.aspx?regexp_id=2706

No whitespace is allowed in a string

This might seem like a contrived example but it was written to answer a question on a forum. For regex newbies you can just change the numbers in {} to change the number of required digits to suit your requirements

This is a simple regular expression which allows 1 to 99 in .5 increments which I originally developed for a forum post

Based on the source listed below. I have added in the 05 prefix for allowing UK voip landlines. I dont know if the spacings are all ofcom approved like the original regex but the patterns it supports are: 029 99999999 or 029 9999 9999; 0199 9999999 or 0199 999 9999; 01999 99999; 01999 999999; 019999 9999; 019999 99999; 0599 9999999 or 0599 999 9999; 05999 99999; 05999 999999; 059999 9999; 059999 99999;

Based on ip regex listed in source. Expanded to require udp:// or norm:// protocol at the start and :12345 port number at the end (1-5 digits). Written to answer a forum question. Current limitations - only allows lowercase protocol names and doesn't block ports that start with 0.

This was based on the regex in the source but it was buggy so I fixed it and then optimized it. It matches port numbers in the form of :1 to :65535 This is designed to be plugged onto the end of your favourite url regex because when I was looking for a IPv4 regex I noticed that a lot of them either didn't match the port or matched it badly (allowing the port number to start with a 0 or be higher than 65535) This regex solves those two problems.

This is the same as my regex listed in the source except that it is wrapped in (regex)? which makes it optional. The intended use for this regex is to be combined with buggy url/ip regex's to strengthen the port matching. It matches port numbers in the form of :1 to :65535 and also allows no port to be entered. I noticed that a lot of url/ip regexs either didn't match the port or matched it badly (allowing the port number to start with a 0 or be higher than 65535) This regex solves those two problems.

This uses named groups to extract the user and domain portions of an Active Directory user in user@domain format. You can use the following c# code to convert this into domain\user format: public string ConvertUserAtDomainToDomainUser(string userAtDomain) { return Regex.Replace(userAtDomain, @"^(?<user>.+)@(?<domain>.+)$", @"${domain}\${user}"); } This regex is intended to provide extraction from valid user@domain strings rather than validate its format.

This will match a youtube url and pull the video id out into a named capture group called VideoID. It is intentionally loose on the length and content of the video id so that it doesn't break in the future if YouTube change the format.

Allows http and https, bans www prefix, username portion is clamped to the rules it gives you at signup and also allows an optional trailing slash. [UPDATED] allows the #! notation that twitter used.

Validating a Facebook page can be a little bit tricky. This is because there are two valid formats. The first is facebook.com/pages/USERNAME/numbers/, the second is designed for big business which grants them a clean url such as facebook.com/coca-cola/. I see this regex being used in a user profile admin page and I think it does a good enough job for this purpose. The problem is bad urls could slip through which meet the criteria for the clean facebook page url but aren't in valid pages on the site. The main example being that an incomplete numbered url could slip through as http://www.facebook.com/pages/ would validate. Facebook also uses various subdomains such as en-gb.facebook.com to provide localised versions of the site. This regex will accept a prefix of either www or a locale code of two letters dash two letters. It doesn't validate the actual country code though. [UPDATED] Added full stop to list of valid characters for page names.

Because a regular expression only deals with a single character at a time it can be a challenge to work with numbers as they often contain multiple digits. This regex allows any number except the numbers in the list. It does this by using a negative look ahead to fail the regex if it finds an excluded number.

This is an intentionally loose implementation. The number in the middle (account num) is constantly increasing as new accounts are made. The number on the end represents the profile number which shouldn't go over 50 but I haven't locked this down so that both elements are future proofed.

Add this on to the end of your url rewriting regex to allow an optional querystring to be appended to whatever you are matching. Useful for example when you set up a Google PPC campaign and all of your urls break. Note: doesn't handle #fragments.

Designed for asp.net default document matching. It allows either a plain url (~/) or a default document url (~/default.aspx) both with an optional querystring. Cassini and IIS7 handle default document matching differently. The user could type it either way. The breadcrumb / sitemap system is funny about omitting default.aspx. Note: Doesn't handle #fragements

The postcode district is the first block of a UK postcode. For example with DN55 1PT it would match DN55. Its a loose match as it only ensures that the format is correct, it doesn't validate the letters and numbers. It doesn't let in the non-geographic codes postcodes SAN TA1 and GIR 0AA. It will pull out the first block of any of the matching examples below. Examples of the names of the different parts of a UK postcode can be found here: http://en.wikipedia.org/wiki/Postcodes_in_the_United_Kingdom#Life-cycle_of_post_codes

The postcode sector is the first block (the postcode district) of a UK postcode plus the first number of the second block. For example with DN55 1PT it would match DN55 1. Its a loose match as it only ensures that the format is correct, it doesn't validate the letters and numbers. It doesn't let in the non-geographic codes postcodes SAN TA1 and GIR 0AA. It will pull out the first block & the sector code of any of the matching examples below. Examples of the names of the different parts of a UK postcode can be found here: http://en.wikipedia.org/wiki/Postcodes_in_the_United_Kingdom#Life-cycle_of_post_codes

UK Parcelforce delivery tracking code for internal UK posts. Comes in two formats 2 letters and 7 numbers (e.g. AA1234567) and 4 letters and 10 numbers (e.g. AAAA1234567890). Case insensitive.

UK Parcelforce delivery tracking code for international tracking of exports. Comes in two formats: 2 letters and 9 numbers and GB (e.g. AA123456789GB) and 12 numbers (e.g. 123456789012). Case insensitive.

UK Parcelforce delivery tracking code for international tracking of imports. Uses a negative look ahead to prevent it ending in GB which would be an international export code.

A combined version of my other three Parcelforce tracking code regexes listed on this site. Uses named capture groups to capture and identify between UK tracking, international export and international import tracking codes. Case insensitive.

TNT UK delivery company consignment number tracking code for TNT Track and Trace service. The system will use the 9 digit code (e.g. 123456789) or you can use the letters as shown on your consignment note (e.g. GE123456781WW). Case insensitive.

Uses named capture groups to extract components. More information on the components meanings can be found on the wikipedia page list in the source.

As listed in on the UK UPS tracking help page (listed in the source)

Uses named capture groups to parse an S10 (UPU standard) code which is the tracking format used by many postal services including the United States Postal Service and most European Postal Services. Full spec in source link.