Sure, the SSN is used a lot but it's normally more for things on the level of bank accounts or signing up with a new employer, where there's some serious investment and need to validate your identity. When you enter it into a website, it'd better be for an important reason.

The CPF is something you might use at the grocery store when buying a piece of fruit in the hopes of winning 1000 BRL from the government for helping the store prove that it's paying its taxes. Go to SP and every shop will ask "CPF na nota?" True, you can just answer "não obrigado/obrigada" but from what I saw, most people give it out.

You just don't see that same level of usage in the USA. You're not going to wander into some store and have the shopkeeper ask for your SSN as soon as you get to the counter.

I dont bother being secretive about SSN, its security theatre. The person in earshot has a lower likelihood of bothering with it when every service provider that also has it will get mass hacked and are the primary targets.

I use a separate TIN or EIN (Tax/Employer Identification Number) where I can. All my businesses have one, even a sole proprietorship that exists purely in your head can obtain one, and this can go on many forms.

Interesting, if you get paid on another TIN does it effectively become your main SSN? What about at retirement time? Would like to hear more about this.

“Effectively become your main SSN” no but loaded question. less places would have your ssn or tin. the only difference it really makes is peace of mind and relying on the current reality that hackers aren't targeting you or anyone specifically and you will have an additional way to verify yourself if someone did try to do identity theft or whatever you’re worried about. Online People databases will still be reporting pieces of your older SSN while you have been primarily giving services a different number.

retirement time isnt a problem. if your business is getting paid and the person that pays needs your tin/ein then thats what they get instead of your ssn. You are still paying self employment taxes contributing to retirement.

EINs don't accumulate Social Security, but when you file taxes you'll pay "self-employment tax" on earnings from that "business" and those go to your personal SS account.

When you use an EIN you're basically claiming to act as a business. For some cases, you can do that just fine. But a lot of SSN requests for identification or credit checks it won't work. And anyone who cares that it's a SSN vs a TIN can figure that out easily.

But the American SSN, while abused, is still supposed to be a secret.

I don't believe the Brazilian CPN is meant to be a secret at all. It's used for literally everything.

In America, you don't give your SSN to your utility company or when signing up for an online subscription. But in Brazil, you use your CPF to do that.

> In America, you don't give your SSN to your utility company

You do where I am, because they run a credit check to determine whether you need to pay a deposit.

Legally is not supposed to be used for identity at all, except for Social Security (and IRS) purposes. But in practice that doesn't happen and it's not particularly secret. Used to be pretty common for people to include it on their pre-printed checks. When I was in college it was used as the student ID number. This was all before "identity theft" was really a thing people worried about.

But SSN should not really intended to be secret. It is not designed to be a proof of identity, but so many companies have treated it that way that it gives more access than it should. If we could prevent companies from using it like a password, it would no longer be a major risk to have it exposed.

I love being asked to verify my SSN just to access my own information through an unknown entity that will not disclose who they are.

SSN's aren't really secret—you can find someone's pretty easily by going to a data broker.