That's definitely some IANAL advice that should be supercede by one's lawyers advice. For example, it's well known for those moving to Puerto Rico under Act 20/22 that the safest bet in case you would ever get audited is to close your USA bank accounts to cleanly sever the connection. This applies even if you get new ones from Puerto Rican branches of the same. Once you're being audited, all of these factors are plugged into the formula and this is definitely is one of the factors used in determining if you are still substantially connected to the United States.
The IRS also looks at if you have joined a church or other social organization in PR. That's a rough one for me if I get audited. While I didn't end up going to PR, I left the country two years ago and during an audit I would not fare well not being able to point to any social organizations, relationships with the opposite gender, or friendships I have overseas even though lawyers suggest setting all of these up. I'm not that social so I'm at risk and hope I don't face an audit. (Covid was a big factor in avoiding social contact too.)
Although all the about is IRS related, I think it's well established that states often work with the IRS procedures as inspiration for their own
That's quite out of scope of the California thread though, as it is a much more complex situation. Income in PR is not subject to US taxation (even federal) so it's quite unlike moving in or out of a state like California.
Just saying the evidence the IRS wants that you are a bona fide resident of PR is in many cases identical to what a state auditing you wants to see to prove you live in another state legitimately.
The IRS also looks at if you have joined a church or other social organization in PR. That's a rough one for me if I get audited. While I didn't end up going to PR, I left the country two years ago and during an audit I would not fare well not being able to point to any social organizations, relationships with the opposite gender, or friendships I have overseas even though lawyers suggest setting all of these up. I'm not that social so I'm at risk and hope I don't face an audit. (Covid was a big factor in avoiding social contact too.)
Although all the about is IRS related, I think it's well established that states often work with the IRS procedures as inspiration for their own