There was a time not so long ago that a person’s mailing address was considered the most reliable way to reach them. That was because prior to 2000 people physically moved less often than their telephone number changed.
With the advent of cellular technology I suspect people phycially move just as often, but no longer need to change their (mobile) numbers. So nowadays, a mobile telephone number is a more reliable way as contact information than a mailing address.
I’m not sure that this is any longer an answerable question if referring to people in general.
When the only ways to reach someone (assuming they were too far away to shout at) were post office mail and telephone, nearly everybody both opened their mail and (if they were close enough to hear it) answered the phone. Now there are more ways to reach somebody than I can plausibly list, in part because there’s probably something new I don’t know about yet; but no individual person uses all of them, and there’s no single consensus technique that will reach everybody. Some people answer their phone/check their voicemail; but even some of those have multiple numbers and only check one of them. Some people read their email; some of those only check one of multiple apparently-active addresses; some don’t check it at all, or glance at it so fast that they’re liable to miss anything unexpected. Some people read their snail mail, others dump it straight in the recycle. Some only pay attention to texts and ignore voicemail; others ignore texts, or can’t get them. Some people keep up with facebook posts, or twitter, or instagram, or whatever’s new or old on the social media block. And for any of those as well as for whatever I’ve left out, there are significant numbers of people who either don’t use them at all, or effectively don’t use them because they rarely or never pay them any attention.
I think you pretty much have to know the person. And, if it’s somebody you haven’t communicated with in a while, they may well have changed their habits in this area; so even that isn’t much help.
(My mailing address and one phone number date to 1987; my email addresses to 2008. I first had email in 2002, but lost those addresses when I switched from dialup to DSL; had them forwarded for a while, but eventually quit doing that. And my mobile number changed about four years ago, because I switched providers and although I tried to transfer the number it refused to transfer.)
If you call someone, you get instant feedback about whether or not you have reached the correct person (assuming someone answers).
If you send someone something in the mail, if the person is no longer there it is entirely possible that you will not get any feedback at all (no forwarding address, the person that is there just tosses the mail instead of sending it back to the post office, etc). If they receive the mail but choose not to respond, you also get no feedback whatsoever.
If I’m looking at an old address book from the year 2000, and the entry is for a twenty-something living in an apartment, that address is practically worthless. A professional private investigator probably wouldn’t follow that lead. Ditto with a landline number. I would sooner cold call a number from the white pages.
But then again, I feel like a person in 1990 would do the same thing if he was looking at an address book from 1970. Except back then the white pages would be a physical book.
Long ago companies started needing a phone number for their account look-ups. All we had back then was our landline, which is now of course not in use. We still have to remember what it was, because changing the numbers on the account is a pain in the ass. At least we don’t get telemarketing calls on this number; in fact I’ve given it out recently.
I’m also concerned about giving out email addresses, since ours is tied to our ISP and would be lost if we move out of their service area. An independent Gmail account would be a better choice.
I’d ask the OP what he thinks “reliable” means and what failure is he trying to avoid?
Do you mean “durable”, as in least likely to change over time unknown to your correspondent? Or do you mean most likely for the message to be delivered assuming the address/number is still valid? Or most likely to be actually noticed by the human you’re trying to reach? Or which method has the best provisions for notifying others when a change is made and for forwarding subsequent messages from the now-obsolete address to the now-current address?
All of those are different aspects of reliability and each has different answers.
This is why most forms nowadays include the question “What is the most reliable way to reach you?”.
As for email addresses, there’s an added complication: My personal gmail address has stayed the same since I got it over a decade ago, and I do not foresee it ever changing… but that’s not the only email address I use. I also have a work email, that I use for most work purposes, and that changes every time I change employers. Of course, for some purposes, that’s exactly what I want: If, as part of my old job, I signed up for something that made it necessary for someone to be able to contact me, I might not want them contacting me after I change jobs.
My wife had to do this with her last phone because of mess ups by both T-Mobile and Verizon and three days of no service. Never ever again. I could not believe how many web sites would not let you change your phone number without texting your old number a pass code. Little tough when that number doesn’t exist anymore. So that meant phone calls, waiting on hold etc., for credit cards, banks, doctors, insurance. Total pain in the ass. I wouldn’t change my phone number for any reason now.
Because the existing accounts are based on the old number, so if you want to bring an old account to a new phone, you need the old phone to approve it. As far as they’re concerned, that’s the only way to prove it’s you.
I’ve had my same number for close to 30 years now. Back then I started with Sprint and I could choose my number from what’s available. I chose a number that didn’t have a 0 or 1 as the second digit of the exchange, e.g., it didn’t start with 505 or 319. To my mind it seemed like a more ‘normal’ phone number.
A couple of years later I got a cell phone for my kids and I choose another number. But the Sprint representative said that in like 1-2 months the next sequential number would become available. So, e.g., if my number was 555-1212, then 555-1213 would become available in 1-2 months. So I snagged that number when it was available.
I’ve had those numbers for years and now 555-1213 is my wife’s number (the kids wanted a different area code for their phones so they got new numbers).
Through the years our providers have changed. At times we both got work phones paid for by our companies and we transferred our numbers to the corporate accounts. My company said that they would keep the number were I to leave, but I said bollocks to that and I was able to keep my number after 10+ years with that company. It’s mine dammit!
My wife and I have had 555-1212 and 555-1213 for over 20 years now. I then got a Google Voice number and that’s what I use for work. It’s also on my LinkedIn profile. That way 555-1212 remains protected.
I’m 61 now and plan to have that number for the rest of my days. And when I kick the bucket I’ll have had only one cell number for my entire life.
Exactly. If an account has two factor authentication, they want to send the code to your old number, since that is what they have on record. It’s really silly because once you actually get thru to a live person, all they ask is your birthdate or last four digits of your social security number and it’s changed in an instant. Why not just add that to the website so I don’t have to sit on hold for half an hour?
Because those other factors are readily available to scammers. if they enabled their website to enable acount changes based on those other factors, any moderately competent script kiddie could steal a few thousand accounts per minute. By making anyone trying to update their phone number talk to a human, that makes it uneconomic for computers to do the work. Even with real live 3rd world scam artists, their criminal productivity is limited by how slowly the e.g. bank’s customer service workers are.