Comment by Yarnage | Hacker News Reader

Comment by Yarnage | Hacker News Reader

Parent Full thread

I'm actually impressed it came back with my correct information. On major websites including Target.com, they do not see my zip code as valid even though it's close to a decade old. Sure, it's knew in the grand scheme of things but that's crazy...

Anyway, I agree with the others that while this is nifty it won't always be accurate for everyone. For instance my township is contained within a very, very large county so typically mail is addressed to the specific township rather than the county. I do not know how or if that could even make a difference but our local post office has suggested it.

Overall pretty interesting idea. I think using this plus a way for users to validate the information found it could be useful. The only thing I would be wary of is the website is technically sending a third party the user's information. Your service could then build up information regarding a website's typical customer. Probably not something to worry about but I know most of the places I've worked at they WOULD NOT allow this; they downloaded their own offline zipcode lookups.

EDIT: Perhaps a way to download and get offline updates would be helpful especially if your website went down.

My understanding is the whole point of a zipcode is that city and state on a mailer don't matter at all. Doesn't zipcode go to a specific post office?

I believe to a point it matters. In high density areas there might be a few distribution centers for mail. So the 9 digit zipcode is important. Also, the address lines are still very important. i.e. 1234 mystreet st. apt #2

Depends on if you mean ZIP or ZIP + 4 or ZIP + 4 + delivery point.

ZIP alone will route to a post office, but here are a significant number of areas where city is needed to further disambiguate due to duplicate street addresses in a delivery zone. Now, they obviously try to avoid this, but it still happens.

ZIP+4 would obviate the need for city, state.

ZIP + 4 + delivery point would obviate the need for everything :)

(The need for delivery point is because even a single address may have multiple mailboxes, etc)

Do you have an example of where city would clarify a zip code further? I'd expect large cities to be the case, but New York, NY seems to get everywhere, so maybe it's country roads? And state is certainly unnecessary, are there any zipcodes that cross states?

That is my understanding as well. The person at our local post office recommended putting the township but wasn't aware of exactly why.

My suspicion is that it doesn't matter one bit but I don't know anything about the USPS system.

Reply on news.ycombinator.com