Do not use this site, just verify phone numbers yourselves directly with the parties involved. You cannot determine the validity of a number through this site, nor learn any verified and accurate information either. Any verifiable facts you share yourself will be promptly responded to in an extremely hostile way by a group of trolls who continuously monitor the site to harass, insult, brigade, and throw accusations at people without reason rather than helping in any way to add and verify information.
After receiving a call from a number that differed from my bank's usual numbers, I grew suspicious and paranoid about it and decided to double-check if it was legitimate. Before separately calling the institution directly through their normal numbers, I quickly googled the mystery number and grew concerned at the comments about it on this site, where people's experiences were very mixed. However, I did manage to confirm the call's validity with my institution afterwards, so I went back to leave a comment in case it was helpful.
I was immediately harassed and accused of being a scammer by the aforementioned group of trolls, despite already stating in my comment that the institution didn't (and wouldn't ever need to) ask for any personal information, and that they only called from the number to confirm all of the details they already had for my transaction. I also noted that the only way to be safe and to know if the call was legitimate is to call back through a known phone number instead, but these facts were all ignored.
Always verify phone numbers directly with parties involved, don't leave it up to random internet trolls and spammers. All this site does is instill unnecessary confusion and paranoia in people rather than giving out a common sense approach that solves all concerns: Don't respond to random calls and never give out your personal information, nor ever believe random crowdsourced information online. Let it go to voicemail, and if it is of relevance or concern to you, contact the appropriate parties or authorities via known numbers instead. This approach solves problems. Meanwhile, 800Notes only causes problems.