Experience and a quick Google Images search suggests that it's standard to provide two fields for Address/Street. A colleague argues that it's perceived as two alternative addresses, and that the fact that there's only one country, state, zip, phone just makes it more confusing. I tried to think of a good explanation for having two fields but couldn't. To the reason of "there are some very long addresses" he replies "then why don't they use a multiline input field which would make it clearer that it's the same address".

So, what's the reason? And is it only standard for the US or for Europe as well?

  • 4
    It's standard for Europe too. As an example I use the first line for my house number and building name, the second line for my street address. Asking for state is often redundant in the UK as postcode will do the trick. When living in Australia I had no street address instead using RMB or RSD code (country mailbox where it is not near a house). There are 2 reasons I can think of. 1. To reflect how you would write the address on a letter (hoping it will be interpreted that way) and 2. Because of the wide variety of possible address formats.
    – Jay
    Commented Jul 10, 2012 at 9:48
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    It's probably a legacy of various database systems that the forms hook into. That too is probably a legacy of various paper-based address forms. It's very hard to programatically split a one-line address into the various lines the DB requires for an address so the form is designed to match the DB. It probably comes down to the old "well that's how we've always done it" and it's now too embedded in the technology infrastructure that to revert to a more simpler method is just too big a change to make.
    – JonW
    Commented Jul 10, 2012 at 10:06
  • The USPS generally uses a "smallendian" approach to addresses. The most minute part of the address at the top, the most general at the bottom. When sorting and delivering, they work their way up, first with ZIP, then Street Address/PO Box, then Addressee. If the ZIP is incorrect, that will delay delivery more than anything. If the city is wrong, it still goes to the right ZIP first, then street address (as long as it makes sense for that ZIP).
    – Taj Moore
    Commented Jul 10, 2012 at 17:05

6 Answers 6


The two fields are part of the same address. (I've never heard your colleague's interpretation before.) Usually the second line is optional.

As noted by dnbrv and TJH, in some locations the second line is necessary or helpful. In addition, providing the extra line allows for formatting an address to optimize postal delivery, which is largely driven by automated scanning of package/envelope labels. Some post offices have preferences about what goes on its own line; while something addressed to "Such And Such Building, Suite 42, 1001 Main Street SW" all on one line will get there, it might get there more quickly if the street address is on its own line. If a form is asking for your address because it might generate physical mail, this would be a reason to provide the extra optional line.

  • One small issue with that, they do not label the fields correctly, so basically it is up to the user to fill out whatever in each field, that kind of defeats that purpose
    – Ayyash
    Commented Dec 20, 2016 at 10:18
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    @Ayyash oh, I usually see them labelled as "address line 1" and "address line 2" or similar. If they're both labelled "address", or if they're unlabelled, that would be confusing. Commented Dec 20, 2016 at 15:10
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    well thats the problem, line1 and line2 say nothing, I could easily put my name in the first, and my street address in the second :)
    – Ayyash
    Commented Dec 20, 2016 at 15:13

I found quite a detailed reference of mailing address formats from around the world but I'm not sure how up to date it is, so I found also a tool to look up address format by country.

Skimming through both, you can notice that the overwhelming majority of countries do need only one line for street address. However, if the destination is a post office (PO) box, then an additional line might be needed. Also, most Spanish-speaking countries, some Southeast Asian countries, and some ex-USSR countries have multi-line addresses. Some of these contries have longer street addresses and others have longer locality formats.

The common practice in the USA is to put apartment/unit/mail stop number on the 2nd line. We also have some street named after Native American locations (e.g. Connecticut, Massachusetts, Massapequa) that tend to fill up the allotted space in the form field, which forces the use of the second line.


It's common in Europe (I'm in UK) too, but usually as an optional field. To give an example of a UK address which requires 2 lines:

Apartment 10, Derp House (line 1)
20 Derpstreet (line 2)
Derpville (Town)
Derptown (City/County)
D3 3RP (Postcode)

I don't know enough about US addressed but my Canadian address also needed the extra line as I lived in a general delivery town, so line 1 had to include my name in case the shipper didn't by default.

In answer to the choice of textbox or text type input I can't really help - I guess it all goes back to DB fields and has just become the standard. That alone is, for me, good enough reason to stick with it - a lot of UX is just about making the experience familiar to the user and not letting them get confused or intimidated by things that are out-of-the-norm, however, I agree a multi-line field does make more sense if the reasoning is that some addresses are long.


In the US, two lines are often provided to allow space for parts of the address which don't fit/belong on a single line such as 'apt 10' or 'suite 1B'. It can also be used for instructions to the package carrier such as 'SIGNATURE REQUIRED'. It is usually optional, and not required if the address field is for a form such as billing address verification, especially when only the zip code would be verified.


As everyone has already said, it's usually required only by the backend.

And yes, your colleague was right, users WILL get confused and think that you are asking for two different addresses if you word the lines like this: "Address 1" "Address 2"

A better way to word the fields is like this: "Address" "Apartment, Suite, Unit, Etc. (Optional)"

This way people realize what the second field is for, and that it's optional.


It is needed as there is no common format for mail addresses and even official rules aren't correct. e.g. My UK address does not fit into the UK Post Office's recommendation

To see even more cases of where a fixed form fails see Falsehoods programmers believe about addresses

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