Never Give Stores Your Zip Code | Hacker News Reader

Never Give Stores Your Zip Code

forbes.com

47 pointsdraker54 comments

I'm located in Germany and when asked I (and others I know) always say 25869. That's Germany's smallest zip code, a remote island with only 5 people living there. Stats should look funny for that zip :)

What's the smallest zip in the US?

Nice idea :) i hate it when I'm asked for my zip code even for small purchases, so I give a random one. I'll do it line you from now on.

US zip code 20050 only has one house.

(The White House)

Or if you're in the southwest, I recommend 78266, which is Büsingen, a German enclave in Switzerland.

I always give them 4711 (a brand name for a very famous German Eau de Cologne, http://www.4711.com/index.php/en/).

Quite often they don't even get it.

If you use the same zip code every time, they still know who you are.

While funny indeed, statistically speaking you'd be giving them the least amount of information by supplying the largest zip code.

Had some 'fun' with this in the UK a while back.

I needed a modem there and then so went to a high street electronics store. I got the empty box of the one I wanted down from the shelf, took it up front, paid and they went to get me a full box from the back. 10 minutes later and the assistant comes back. They have no modems.

This is mildly annoying, but fine, so I asked for my money back, which is when they started demanding my name and address. When I refused the assistant went to get the manager, who said they needed the details to process a refund. I said it wasn't a refund, you took my cash without giving me a product. I offered to call the police if this was giving them trouble and then it came down to "well the software won't open the till without an address".

So... it's some programmer's fault!

You can usually invent a post code that is valid.

All major post offices have a suffix of 1AA.

For the prefix, you can usually use the letters from your prefix but change the number to a 1 and if applicable any letters that follow the number to an A.

So if your postcode is WC2E 9AB then just give WC1A 1AA.

Voila, valid post code for the main post office in any area.

Edit: This is legacy, a lot of the 1AA post-codes were recycled in the 1960s when the post office underwent major re-structuring. It still works though.

I eventually told the manager it was her problem and she should invent an address. She appeared to agree with me, pressed a couple of buttons and asked for the address again, so I made one up out of exasperation at the whole thing.

--edit-- thanks for the tip though, didn't know about that before.

It's kind of crazy that people expect to go unidentified after having used a debit or credit card with their name and a globally unique id on it. Anyone who cares at all about it should have used cash.

Credit Card companies have rules in their merchant agreements that prevent companies from using credit card numbers as unique identifiers.

The last four digits of your CC is ~13 bits, the type of card a few more. That, plus your name, and they should have a fairly good ID for you.

When I worked in retail we asked everyone for their Zip code regardless of their payment method. We were told that it was so that the store could determine where their customers were coming from. Half the time we would just type in the store's Zip Code so that we didn't have to bother the customer.

Gas stations on the other hand use Zip Codes as a way to prevent fraud. I've had my card rejected before by typing in the wrong Zip Code.

> Gas stations on the other hand use Zip Codes as a way to prevent fraud.

This also locks out customers with a non-US address (e.g. tourists) which often don't even have a 5-digit zip code or store it differently so that the check will fail, arguably defeating the entire point of owning a credit card.

I'm not sure if this is always the case.

ZipCar (a short term rental car company) provides a credit card that can be used to pay for gas. When you insert the card at the pump, the machine only asks for your ZipCar membership number.

This leads me to believe that perhaps a card that was issued in a foreign country might prompt the user to enter something other than a Zip Code.

Nope. I've done this with a Canadian card. It prompts for the zip code (at least, at many gas stations along the east coast).

If it's any consolation most american tourists can't use their CCs in European gas stations (the automated pumps require a chip). And one attendant didn't even know how to swipe the card in the reader. Poor girl had to call her manager at his home.

That's a shame. I've always given my ZIP code when asked, on the theory that the retailer was using that information to determine where to open new stores. If that's not the case, then they can have fun sending their snail-mail spam to my namesake in 90210.

If you ever need to return something they are entitled to your ID which has your entire address anyway.

If they ever swipe your license on their mag scanner, it contains everything about you.

Your state DMV sells your info to corporations for pennies, in fact sometimes under law it's required to.

  If you ever need to return something they are entitled to your ID which has your entire address anyway.

Says who?

Or here's another scenario, which actually happened to me:

I bought office supplies and one of the items bought was accidentally scanned twice.

I noticed this after paying, but immediately complained.

In order to refund my money for her mistake she insisted I provide my name and address.

I lied. I very obviously wrote a non existing person at a non existing address on the form she insisted I fill.

Do you think I was unjustified to lie in such a situation?

  Your state DMV sells your info to corporations for pennies, in fact sometimes under law it's required to.

Not in Europe, they don't. In fact: This would be illegal, if not actually criminal.

They do actually do this in the UK

http://www.telegraph.co.uk/news/uknews/9994089/DVLA-made-10m...

This is how car parking companies get your home address from your number plate to write you threatening letters.

  The agency sold the details at a rate of around 50,000 a week, totalling 2.4 million in a year, to approved companies that give out parking fines and clamp cars.

Key here is probably "approved company". Even though: I admit it's a slippery slope.

If they just sell such information to any shyster that asks (and pays) for it there probably would be quite an uproar and it would almost certainly be counter to the EU data protection directive.

Approved company usually just means a BPA registered company, This is a trade organisation made up of parking companies that has no government affiliation at all. It's so parking companies can make a formal set of rules they agree to oblige to self regulate with and avoid the government making real laws to stop these people.

It really doesn't mean anything.

Do you think I was unjustified to lie in such a situation?

In the US (may be state law and not federal) it is a felony to give a false name/address for returns.

The reason why is people steal stuff or buy it cheaper in one store and then go to another to return it for cash.

However most stores do not require name/address if you have the original receipt. Only for no receipt.

Doesn't everyone just fill in 90210?

or does give away my age...

There was a show called "90210" (a Beverly Hills 90210 spinoff) that Wikipedia says just ended last month, so choosing that shouldn't show your age. (Although your question obviously did.)

that's not the 90210 he was talking about

123 Main st, Vancouver, v1v1v1 gets a lot of junk mail because of me.

or V4G 1N4

As a non american, this is the first american postcode I can think of off the top of my head.

I've actually suspected this for years and my simple and polite response is, "No, thanks." or "I don't give it out."

Same. And I've always been willing to walk away, and usually have a polite conversation with the check out person to help them understand why it is bad.

Harvard's Data Privacy Lab runs a simple "identifiability" web site.

Submit your DOB, sex, and zip, and they'll tell you approximately how unique you are therein, based on Census data.

http://aboutmyinfo.net/

Giving stores a false but consistent zip doesn't help, but using a new one every time might. Or, if we could all agree on a false zip to use, that would skew the data away from Census-based estimates. However, with DOB and gender data, it might just ID us uniquely within the adopted HN zip code.

I'm unable to produce the research link, ATM, however I attended a presentation many years ago on the uniqueness value of this data. In the presentation the researchers demonstrated >80% confidence interval determining an exact individual from: (1) gender, (2) birth year, and (3) zip code. I recall the interval was for zip codes with the greatest population density, implying that more confidence was readily achievable in less populated zip codes.

This is a nice demonstration of the information explosion, which is the best reason for privacy concerns. You hand out your zip code, probably figuring that not much can be deducted from that and suddenly, they know your address, from there on they can get an idea about your income (think about rent), maybe about your general background and so on and so on. It's scary to think about it like that.

Doesn't this article completely miss the actual glaring privacy issue that there is a database of name-address-phones out there that is complete enough to only have a few duplicates that a simple zip takes care of?

Giving out your zip shouldn't be that big of a deal, the reason it is is because your name and address is listed on whitepages ;)

That database is pretty much inevitable in the US, unfortunately. Even if you don't list your name and address anywhere, it's easy enough for companies you do business with to sell your details to such a database.

whitepages? My cell phone is not in the whitepages and I haven't had a landline for years.

What if you just said something like 98123 give then the a fake one? What would be the harm in that ?

This is one thing I like about shopping at Amazon and Newegg: I never have to worry about them using my zip code to find my address for marketing purposes.

edited

Cashier: May I have your Zip Code? Me: F* no!

Did you read the article? It's often the key to gaining your whole address for marketing purposes.

edited my post

Does swearing make you feel more grown up?

Wait, I thought colorful language was how humans displayed sexual maturity? Much the same way that a peacock displays its colorful plumage to advertise its quality as a mate?

Only when their sexual maturity is in doubt.

Does being the language police make you feel more grown up?

No, but successfully trolling three people while making my point does!

Are you sure you know what website you're on? Have you forgotten you have identifying personal information in your profile? What do you anticipate future employers' reactions being to discovering you are a proud troll? Do you really think they'll want to work with you, or have your name associated with their company?

My ZIP is 98104. That should be able to get you my home address, if the noted PII is not sufficient for you.

I don't want your home address, I want you to realize this isn't reddit, 4chan, or whatever other group home for thugs has convinced you that deliberate antisocial behavior is normal or acceptable.

Then you shouldn't have participated in that behavior.

Does avoiding swearing make you feel more grown up?

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