Formatting UK postal codes for storage

Question

I want to store UK postal codes in the database. Is it OK to store those postal codes without the spaces?

Answer 1

Last 3 are always xyy

• x Digit 0-9
• yy Alpha A-Z

Anything before is the first part of the grid reference and has various formats.

Answer 2

It is possible to store postcodes without spaces, but would definitely recommend formatting them correctly when they are displayed/output.

You can check out the allowed formats for postcodes here . There are always 3 characters after the space so it's easy to reinsert it.

Answer 3

It's usually safe to remove the space. As others have said, you can re-insert the space later if required. The existence of a space between Outcode and Incode will not normally affect postal delivery. You should not have any non alpha numeric characters in a UK postcode, so if you see a dash you can safely remove it.

I work for Experian Data Quality and if your aim is clean data you may want to consider an address verification web service, like our Pro On Demand product. This will ensure you capture the correct postcode, as they can change over time, and that it is formatted correctly for your database.

Answer 4

It is okay to store without a space because you can always add an empty space back in to each postcode string - the heuristic is pretty simple.

As some other users have very helpfully explained, all UK postcodes have two groups of numbers and letters, separated by a space. The group following the space always contains a number and then two letters (thus, there are always three characters after the space). The group before the space will have either two, three, or four characters (see this Wikipedia page) and the screenshot below.

So, you can recreate the correct spacing by adding a space before the third-to-last character.

In R, it looks like this (but the same logic would work in other languages, such as Python):

#list of example postcodes
postcodes = c("LS176JA", "OX41EZ", "A99AA")

#add space to each postcode in the list of example postcodes
for (postcode in postcodes){
  last_three = str_sub(postcode, start = -3)
  first_x = str_replace(postcode, last_three, "")
  final_postcode = paste0(first_x, " ", last_three)
  print(final_postcode)
}

Which returns:

[1] "LS17 6JA"
[1] "OX4 1EZ"
[1] "A9 9AA"

Answer 5

we store postcodes and we accept inouts in any format, space or no space, but then strip or correct the entry for data storage

we find it works better this way when using the data for other things

Why would you want to store with no spaces?

Answer 6

Uk postcodes have a variety of formats: list of formats

Why are you unable to store white spaces?

Answer 7

As others have said, there is no problem with removing all spaces and storing them, if that is what you want to do. As has been said, you can always format them with a space before the last three characters.

However, I would normally take them in any reasonable format, strip all spaces out, and them store them with this one extra space. The storage requirements are not an issue, and it makes it easier to simply display as it is. You would need to resolve the format before saving in some way, so you may as well save it as it is needed.