What does it mean when I'm successor POA?

Yes. Have the "attorney" who drew up the POA, draw up a document, letter, etc... from your sibling stating they are basically handing over the POA responsibility to you, why and for how long. Good luck.

I just want to caution you and everyone else, that being POA may START out being just to do their taxes, or pay a few bills or monitor/assist as your parents ask....however, I speak from experience....when health suddenly declines, or problems suddenly show up, it can get very time consuming VERY fast! I am the only remaining child, so there is no other choice, except to resign and appoint a public fiduciary and pay for them out of parents money....but that will not solve all the communications issues I have to deal with from a dysfunctional, obsessive-compulsive, unhappy, depressed mother, who is having dementia show up in herself right now, while I am active POA for my Dad who needed to be placed in Memory Care....and in the middle of that, we are currently having my husband being worked up for Parkinson's Disease!! And I only started this exactly 2 years ago! Working with a financial person at parents law firm to get Dad qualified for Medicaid to pay the facility; then working the same way to get all the assets just in Mom's name and disbanding their trust...and things have been somewhat stable since December, but this week, I learned that Mom now needs to sign papers for a new trust, just in HER name with me as POA...and that means we must (yet again!) establish new checking accounts and bank cards etc, and get all this paperwork notarized.

So, be aware...as I was NOT....that current health and abilities with parents can change very quickly at their ages.....well at least at MY parents ages....88 yr and 92 yr now....and you can quickly have your POA requirements escalating into more than you thought.....

Whatever reason the 1st POA gives can be used for substitution. I wish your brother-in-law had discovered the pancreatic cancer before this diagnosis. My husband's was caught early due to his symptoms and I took him to Mayo.

I agree with getting a notarized statement from your sibling. Since it appears that your sibling wants to resume POA at some time in the future, the statement should include some provision for that, either a date, or just the fact that this is temporary and will be followed by another notarized statement resuming the job (and it is a job). It sounds like your parents are able to handle most of their affairs, but it is a good idea to try to get an overview of their finances in case the situation should suddenly change while you are the acting POA. A review of their bank statement each month is a good way to make sure that they are keeping up with bills and not losing money to scammers.

GraceH--it is definitely not regulated, although, of course, a thieving POA could be prosecuted (but that wouldn't necessarily bring the money back!). Unfortunately, there aren't enough people (i.e. not enough money) to supervise POAs in counties, usually! If you think about it--it's not as though you file the POA with any office once you complete it. But yes, successor POA is what you think it is. If there is nothing you have to do except taxes, that's good. But in order for you to act on their behalf (e.g. get a copy of a missing 1099, for example), you probably would need, as pstegman suggests, a notarized letter from the primary POA, surrendering the position to you. So definitely ask for that.

The current or 1st POA is just emailing me, which does indeed seem fishy. But my parents say to me, since they are still In Control of their affairs basically, that they want me to do their quarterly taxes. I am working in the financial field so this wouldn't be a problem, however, I am waiting for the POA to send me his files..... otherwise I do have all the paper copies at my parent's house so I can go from there.
But it is an interesting question, when the POA is set up, it gives absolutely no instructions on how things will proceed in Real Life.
Doesn't anyone find it interesting there is no Supervision of POA people, and successors, in the local county offices or, where would this be supervised?
It just seems exactly as it is popularly said, "a POA is a license to steal" unless the POA is committed to doing things for the benefit of the Principal(s).

I think email might not hold up in court, so ask them to send their resignation to you in writing, with a notarized signature.

This sounds like my family. I am alternate POA ( only because my brother refused to let mom put my nephew on as alternate) and they misspelled my name.......talk about being out of the loop. I don't know the dynamics with your family but at this point I refuse to be alternate. So mom will have a court appointed guardian should my brother die. You don't have to accept this responsibility, especially since you have been purposely left out. I gave my mom and brother 6 years to correct the mess we have made but noooooooo......I was not to be trusted. So I am not going to be the alternate. Good luck to you, hope it works out better than my dysfunctional family.

No, they have most definitely NOT kept me up to date, they have purposely not included me in anything. I am starting from scratch, apparently, so this will be interesting.

Yes it does.. Have they been keeping you informed about what responsibilities they preform for your parents? You'll need to get up to date on everything..