根据皇家邮政的程序员指南，检查邮政编码是否为有效格式:

          |----------------------------outward code------------------------------| |------inward code-----|
#special↓       α1        α2    AAN  AANA      AANN      AN    ANN    ANA (α3)        N         AA
^(GIR 0AA|[A-PR-UWYZ]([A-HK-Y]([0-9][A-Z]?|[1-9][0-9])|[1-9]([0-9]|[A-HJKPSTUW])?) [0-9][ABD-HJLNP-UW-Z]{2})$

uk上的所有邮编都匹配，除了那些不再使用的邮编。

增加一个?空格后，使用不区分大小写的匹配来回答这个问题:

'se50eg'.match(/^(GIR 0AA|[A-PR-UWYZ]([A-HK-Y]([0-9][A-Z]?|[1-9][0-9])|[1-9]([0-9]|[A-HJKPSTUW])?) ?[0-9][ABD-HJLNP-UW-Z]{2})$/ig);
Array [ "se50eg" ]

我发现在几乎所有的变化和regex从批量转移pdf和什么是在维基百科网站上是这样的，特别是维基百科的regex是，需要有一个^后的第一个|(竖条)。我通过测试AA9A 9AA发现了这一点，因为否则A9A 9AA的格式检查将验证它。例如，检查应该无效的EC1D 1BB返回有效，因为C1D 1BB是有效的格式。

以下是我想出的一个好的正则表达式:

^([G][I][R] 0[A]{2})|^((([A-Z-[QVX]][0-9]{1,2})|([A-Z-[QVX]][A-HK-Y][0-9]{1,2})|([A-Z-[QVX]][0-9][ABCDEFGHJKPSTUW])|([A-Z-[QVX]][A-HK-Y][0-9][ABEHMNPRVWXY])) [0-9][A-Z-[CIKMOV]]{2})$

^([A-PR-UWYZ0-9][A-HK-Y0-9][AEHMNPRTVXY0-9]?[ABEHMNPRVWXY0-9]? {1,2}[0-9][ABD-HJLN-UW-Z]{2}|GIR 0AA)$

Regular expression to match valid UK postcodes. In the UK postal system not all letters are used in all positions (the same with vehicle registration plates) and there are various rules to govern this. This regex takes into account those rules. Details of the rules: First half of postcode Valid formats [A-Z][A-Z][0-9][A-Z] [A-Z][A-Z][0-9][0-9] [A-Z][0-9][0-9] [A-Z][A-Z][0-9] [A-Z][A-Z][A-Z] [A-Z][0-9][A-Z] [A-Z][0-9] Exceptions Position - First. Contraint - QVX not used Position - Second. Contraint - IJZ not used except in GIR 0AA Position - Third. Constraint - AEHMNPRTVXY only used Position - Forth. Contraint - ABEHMNPRVWXY Second half of postcode Valid formats [0-9][A-Z][A-Z] Exceptions Position - Second and Third. Contraint - CIKMOV not used

http://regexlib.com/REDetails.aspx?regexp_id=260

我看了一下上面的一些答案，我不建议使用@Dan的答案(12月15日至10日)中的模式，因为它错误地将近0.4%的有效邮政编码标记为无效，而其他的则没有。

军械测量所提供的代号开放服务包括:

包含英国所有当前邮政编码单位的列表

我使用grep从这些数据中针对完整的邮政编码列表(7月6日至13日)运行了上面的每个正则表达式:

cat CSV/*.csv |
    # Strip leading quotes
    sed -e 's/^"//g' |
    # Strip trailing quote and everything after it
    sed -e 's/".*//g' |
    # Strip any spaces
    sed -E -e 's/ +//g' |
    # Find any lines that do not match the expression
    grep --invert-match --perl-regexp "$pattern"

邮政编码共有1,686,202个。

以下是与每个$模式不匹配的有效邮政编码的数量:

'^([A-PR-UWYZ0-9][A-HK-Y0-9][AEHMNPRTVXY0-9]?[ABEHMNPRVWXY0-9]?[0-9][ABD-HJLN-UW-Z]{2}|GIR 0AA)$'
# => 6016 (0.36%)

'^(GIR ?0AA|[A-PR-UWYZ]([0-9]{1,2}|([A-HK-Y][0-9]([0-9ABEHMNPRV-Y])?)|[0-9][A-HJKPS-UW]) ?[0-9][ABD-HJLNP-UW-Z]{2})$'
# => 0

'^GIR[ ]?0AA|((AB|AL|B|BA|BB|BD|BH|BL|BN|BR|BS|BT|BX|CA|CB|CF|CH|CM|CO|CR|CT|CV|CW|DA|DD|DE|DG|DH|DL|DN|DT|DY|E|EC|EH|EN|EX|FK|FY|G|GL|GY|GU|HA|HD|HG|HP|HR|HS|HU|HX|IG|IM|IP|IV|JE|KA|KT|KW|KY|L|LA|LD|LE|LL|LN|LS|LU|M|ME|MK|ML|N|NE|NG|NN|NP|NR|NW|OL|OX|PA|PE|PH|PL|PO|PR|RG|RH|RM|S|SA|SE|SG|SK|SL|SM|SN|SO|SP|SR|SS|ST|SW|SY|TA|TD|TF|TN|TQ|TR|TS|TW|UB|W|WA|WC|WD|WF|WN|WR|WS|WV|YO|ZE)(\d[\dA-Z]?[ ]?\d[ABD-HJLN-UW-Z]{2}))|BFPO[ ]?\d{1,4}$'
# => 0

当然，这些结果只处理被错误地标记为无效的有效邮政编码。所以:

'^.*$'
# => 0

在过滤无效邮编方面，我并没有说哪种模式是最好的。

这个允许两边有空格和制表符，以防你不想验证失败，然后在另一边修剪它。

^\s*(([Gg][Ii][Rr] 0[Aa]{2})|((([A-Za-z][0-9]{1,2})|(([A-Za-z][A-Ha-hJ-Yj-y][0-9]{1,2})|(([A-Za-z][0-9][A-Za-z])|([A-Za-z][A-Ha-hJ-Yj-y][0-9]?[A-Za-z])))) {0,1}[0-9][A-Za-z]{2})\s*$)

虽然这里有很多答案，但我对其中任何一个都不满意。他们中的大多数只是简单地坏了，太复杂或只是坏了。

我看了@ctwheels的答案，我发现它非常具有解释性和正确性;我们必须为此感谢他。然而，对我来说，如此简单的事情又有太多的“数据”了。

幸运的是，我设法获得了一个数据库，其中仅包含英国的100多万个活动邮政编码，并编写了一个小型PowerShell脚本来测试和基准测试结果。

英国邮政编码规格:有效的邮政编码格式。

这是“我的”正则表达式:

^([a-zA-Z]{1,2}[a-zA-Z\d]{1,2})\s(\d[a-zA-Z]{2})$

简短，简单，甜蜜。即使是最没有经验的人也能明白发生了什么。

解释:

^ asserts position at start of a line
    1st Capturing Group ([a-zA-Z]{1,2}[a-zA-Z\d]{1,2})
        Match a single character present in the list below [a-zA-Z]
        {1,2} matches the previous token between 1 and 2 times, as many times as possible, giving back as needed (greedy)
        a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
        A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
        Match a single character present in the list below [a-zA-Z\d]
        {1,2} matches the previous token between 1 and 2 times, as many times as possible, giving back as needed (greedy)
        a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
        A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
        \d matches a digit (equivalent to [0-9])
        \s matches any whitespace character (equivalent to [\r\n\t\f\v ])
    2nd Capturing Group (\d[a-zA-Z]{2})
        \d matches a digit (equivalent to [0-9])
        Match a single character present in the list below [a-zA-Z]
        {2} matches the previous token exactly 2 times
        a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
        A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
$ asserts position at the end of a line

结果(已核对邮编):

TOTAL OK: 1469193
TOTAL FAILED: 0
-------------------------------------------------------------------------
Days              : 0
Hours             : 0
Minutes           : 5
Seconds           : 22
Milliseconds      : 718
Ticks             : 3227185939
TotalDays         : 0.00373516891087963
TotalHours        : 0.0896440538611111
TotalMinutes      : 5.37864323166667
TotalSeconds      : 322.7185939
TotalMilliseconds : 322718.5939