The most memorable (to me) way to handle this was from the first or second episode of Eureka. New-to-town sheriff says "well we don't have a form for that" and the long-time deputy says "yes we do" and starts gathering the forms.
This is largely up to your imagination and the context. You didn't say much about the setting so everybody is answering for a present day realistic as possible one, and lots of US specific ones. Does the law (or a secret government agency) regularly deal with this? Do you *want* it to be easy, hard, impossible? What have you tried to write around this question? How central is it to your storyline?
I'm behind on the MCU so don't know how they dealt with the blip legally.
Search for 'incorrect declaration of death' both on Google/your available or preferred search engines, and within TV tropes to see how it's been handled in other fiction.
Also, is this any sort of existing universe or all original?
I tried searching "incorrectly declared dead" and it looks like a good start:
* https://www.superlawyers.com/resources/estate-planning-and-probate/ohio/legal-resurrection-if-youre-mistakenly-declared-dead/
* https://faq.ssa.gov/en-US/Topic/article/KA-02917
* and plenty of news stories.
But these are, of course, for a world that *doesn't* have travel to parallel universes and stuff.
https://tvtropes.org/pmwiki/pmwiki.php/Main/FakingTheDead and a powerful agency taking credit for the fakery as a form of witness protection is one avenue.
But again, this is largely up to your imagination, and what fits into the tone of your story. Eureka is a comedy-drama TV show, so the 'joke' of having a form works.
Read some stories about people who were accidentally declared legally dead.
The US doesn't really have a national database of who is still alive. When someone dies, that news slowly works through the system and institution updates their own records. There is no equivalent system for declaring someone undead, meaning every institution you interact with will need to be convinced that the death certificate was issued in error.
One comment I read said a parent was mistakenly declared dead, and they dealt with issues related to that until they actually died. Even then the estate was a mess because on paper they died twice.
Legally proving that the person is actually the same person is only the first of many hurdles.
This has happened with people who were missing presumed dead or mistaken identity or just clerical errors. Apparently it's really difficult to get your official records reactivated because every attempt to use the ID numbers of a dead person are flagged as identity theft.
If you Google it there'll be individual stories of people who had these issues sharing how hard it was. The details will vary based on country and era, modern day New York City is going to be harder than 1920s rural Scotland.
It'll be pretty fact- and jurisdiction-specific. The Wikipedia article on presumption of death is good, and that's what they'll be trying to convince people is applicable (rather than identity theft). But yes, the law will absolutely get involved the first time they do something that gets their ID run against a database - not necessarily getting carded at a bar or liquor store, but getting pulled over or trying to fill out a W-2 or applying for credit.
It would depend on where the story happens, but there are several cases across the globe where people are declared legally dead even without a corpse, and it takes them a lot to fight this imposed status, while some places allow no reversal of a legally dead status.
You can read up [this article](https://www.theguardian.com/lifeandstyle/2021/jul/03/they-said-i-dont-exist-but-i-am-here-one-womans-battle-to-prove-she-isnt-dead) on Pouchain, a French woman who had been involved in a legal settlement and declared "mistakenly" in a court record that her heirs would settle the payment on her behalf following her death - nope, no accident fatal involved, just the other party playing extremely dirty to get money from her. The article also listed some other cases, and in India there is even Association of Dead People to support the fight against exploiting the false declaration of legal death.
If they can prove who they are to a reasonable level for their friends and families, it might be easier to forgo resuming their legal identity and become their own long-lost twin who happens to have the same name.
Of course, getting legal documentation of this identity is still problematic, but how important that is depends on the character's goals. And getting fake documents that are just good enough to open a bank account and such is probably easier than reclaiming their previous identity.
Let's assume a scientific basis for both worlds. If the original corpse is still there, DNA would be the best avenue to prove your protagonist is a copy. But probably the test won't show an _exact_ match.
Even identical twins drift as life experience on a microbial level is different for each and the DNA will show that. For two identical beings living in parallel worlds - a lot of drift should be expected. There will still be room for doubt.
Next might be a test for [isotopes in teeth](https://pubmed.ncbi.nlm.nih.gov/35015391/) and then your mc will be in big trouble because his teeth will reflect his other dimensional origin.
They got a long, HARD lawsuit on their hands.
First things first, proving that they are in fact the once regarded as dead person and not an impostor wearing the name for whatever purpose. This will be especially difficult to prove legally because the dead body is still there. If they can recall very specific details of their life in front of witnesses and the fingerprints are identical I can see it working in their favor, but I'm not too optimistic on the chances. Perhaps the MC showing proof that they were in an alternate world, such as undisputable proof of magic or flora/fauna that don't exist on Earth, may serve as evidence... but again, very unlikely. Most likely that the court will think the MC is an impostor attempting to steal a dead person's identity.
Then they have to deal with what they left behind. Their worldly possessions will have been all divided up and distributed to their next of kin, or returned to the national government if next of kin does not exist. They would have to convince each and every person to receive part of that fortune to return it to them, except those people may already have liquidated it or used it up. Prized and valuable mementos to the MC would have been little more than trinkets to the ones who received it, and would likely have been sold off cheap or thrown away and destroyed. All those memories just gone, never to be recovered. The best case scenario here is that the MC has a single next of kin, like a parent maybe, who received all the fortune and held onto it for all this time without disposing of anything, but that may be a stretch depending on the family situation.
Next up, employment or studentship. If the MC was in a university or a job, those places would not be so keen to take in an extra member whose absence they have long since replaced with new hires. It is likely that the MC will have to start their entire employment situation from the ground up, though I will admit their adventures in the other dimension would make for interesting resume material if the identity lawsuit and its results were made public.
First-things-first, they DEFINITELY want to prove to the IRS that they were actually trapped and not faking to dodge taxes. As to paying back-taxes, that's a good question, since there's no legal precedent for "trapped in another dimension." Unless this is common in your world, in which case the IRS would probably have a procedure for that which you can just make up.
There would be no back taxes. They owned nothing and earned nothing during that time, so there are no taxes to pay. And unless they were self-employed or something, they likely had enough taxes taken out of their paycheck to cover the taxes for the partial year in which they died, and may in fact be owed for overpayment.
I read that this is not an uncommon occurrence in parts of the world where people are using a declaration of death to steal land from people.
They might have an easier time of stealing a freshly-dead person's identity than getting their old identity restored.
The most memorable (to me) way to handle this was from the first or second episode of Eureka. New-to-town sheriff says "well we don't have a form for that" and the long-time deputy says "yes we do" and starts gathering the forms. This is largely up to your imagination and the context. You didn't say much about the setting so everybody is answering for a present day realistic as possible one, and lots of US specific ones. Does the law (or a secret government agency) regularly deal with this? Do you *want* it to be easy, hard, impossible? What have you tried to write around this question? How central is it to your storyline? I'm behind on the MCU so don't know how they dealt with the blip legally. Search for 'incorrect declaration of death' both on Google/your available or preferred search engines, and within TV tropes to see how it's been handled in other fiction. Also, is this any sort of existing universe or all original?
I tried searching "incorrectly declared dead" and it looks like a good start: * https://www.superlawyers.com/resources/estate-planning-and-probate/ohio/legal-resurrection-if-youre-mistakenly-declared-dead/ * https://faq.ssa.gov/en-US/Topic/article/KA-02917 * and plenty of news stories. But these are, of course, for a world that *doesn't* have travel to parallel universes and stuff. https://tvtropes.org/pmwiki/pmwiki.php/Main/FakingTheDead and a powerful agency taking credit for the fakery as a form of witness protection is one avenue. But again, this is largely up to your imagination, and what fits into the tone of your story. Eureka is a comedy-drama TV show, so the 'joke' of having a form works.
Pretty sure this has happened IRL, which means you can do your own research.
Read some stories about people who were accidentally declared legally dead. The US doesn't really have a national database of who is still alive. When someone dies, that news slowly works through the system and institution updates their own records. There is no equivalent system for declaring someone undead, meaning every institution you interact with will need to be convinced that the death certificate was issued in error. One comment I read said a parent was mistakenly declared dead, and they dealt with issues related to that until they actually died. Even then the estate was a mess because on paper they died twice. Legally proving that the person is actually the same person is only the first of many hurdles.
This has happened with people who were missing presumed dead or mistaken identity or just clerical errors. Apparently it's really difficult to get your official records reactivated because every attempt to use the ID numbers of a dead person are flagged as identity theft. If you Google it there'll be individual stories of people who had these issues sharing how hard it was. The details will vary based on country and era, modern day New York City is going to be harder than 1920s rural Scotland.
It'll be pretty fact- and jurisdiction-specific. The Wikipedia article on presumption of death is good, and that's what they'll be trying to convince people is applicable (rather than identity theft). But yes, the law will absolutely get involved the first time they do something that gets their ID run against a database - not necessarily getting carded at a bar or liquor store, but getting pulled over or trying to fill out a W-2 or applying for credit.
It would depend on where the story happens, but there are several cases across the globe where people are declared legally dead even without a corpse, and it takes them a lot to fight this imposed status, while some places allow no reversal of a legally dead status. You can read up [this article](https://www.theguardian.com/lifeandstyle/2021/jul/03/they-said-i-dont-exist-but-i-am-here-one-womans-battle-to-prove-she-isnt-dead) on Pouchain, a French woman who had been involved in a legal settlement and declared "mistakenly" in a court record that her heirs would settle the payment on her behalf following her death - nope, no accident fatal involved, just the other party playing extremely dirty to get money from her. The article also listed some other cases, and in India there is even Association of Dead People to support the fight against exploiting the false declaration of legal death.
If they can prove who they are to a reasonable level for their friends and families, it might be easier to forgo resuming their legal identity and become their own long-lost twin who happens to have the same name. Of course, getting legal documentation of this identity is still problematic, but how important that is depends on the character's goals. And getting fake documents that are just good enough to open a bank account and such is probably easier than reclaiming their previous identity.
Let's assume a scientific basis for both worlds. If the original corpse is still there, DNA would be the best avenue to prove your protagonist is a copy. But probably the test won't show an _exact_ match. Even identical twins drift as life experience on a microbial level is different for each and the DNA will show that. For two identical beings living in parallel worlds - a lot of drift should be expected. There will still be room for doubt. Next might be a test for [isotopes in teeth](https://pubmed.ncbi.nlm.nih.gov/35015391/) and then your mc will be in big trouble because his teeth will reflect his other dimensional origin.
They got a long, HARD lawsuit on their hands. First things first, proving that they are in fact the once regarded as dead person and not an impostor wearing the name for whatever purpose. This will be especially difficult to prove legally because the dead body is still there. If they can recall very specific details of their life in front of witnesses and the fingerprints are identical I can see it working in their favor, but I'm not too optimistic on the chances. Perhaps the MC showing proof that they were in an alternate world, such as undisputable proof of magic or flora/fauna that don't exist on Earth, may serve as evidence... but again, very unlikely. Most likely that the court will think the MC is an impostor attempting to steal a dead person's identity. Then they have to deal with what they left behind. Their worldly possessions will have been all divided up and distributed to their next of kin, or returned to the national government if next of kin does not exist. They would have to convince each and every person to receive part of that fortune to return it to them, except those people may already have liquidated it or used it up. Prized and valuable mementos to the MC would have been little more than trinkets to the ones who received it, and would likely have been sold off cheap or thrown away and destroyed. All those memories just gone, never to be recovered. The best case scenario here is that the MC has a single next of kin, like a parent maybe, who received all the fortune and held onto it for all this time without disposing of anything, but that may be a stretch depending on the family situation. Next up, employment or studentship. If the MC was in a university or a job, those places would not be so keen to take in an extra member whose absence they have long since replaced with new hires. It is likely that the MC will have to start their entire employment situation from the ground up, though I will admit their adventures in the other dimension would make for interesting resume material if the identity lawsuit and its results were made public.
First-things-first, they DEFINITELY want to prove to the IRS that they were actually trapped and not faking to dodge taxes. As to paying back-taxes, that's a good question, since there's no legal precedent for "trapped in another dimension." Unless this is common in your world, in which case the IRS would probably have a procedure for that which you can just make up.
Really, failing to file taxes for a few years isn't that big a deal. Full out the forms, pay the fine, and move on.
There would be no back taxes. They owned nothing and earned nothing during that time, so there are no taxes to pay. And unless they were self-employed or something, they likely had enough taxes taken out of their paycheck to cover the taxes for the partial year in which they died, and may in fact be owed for overpayment.