Limited Partner incorrectly designated General Partner on K1, should I correct prior years too?

Are you doing any work for the Partnership?  If so, the accountant was right, and you would not be a Limited Partner.

If you are a Limited Partner, yes, I would amend everything.  Depending on the circumstances, it may or may not affect things.

Let's hold on a moment.  Let's get some more facts here.
1) An LLC was formed.  Is this a single member LLC?
2) If 1 is "yes" who owns the single member LLC?
3) Are you saying you (personally) are now going from GP to LP?
4) If  3 is "yes" how has the allocation worked in all these years?
5) Give me some details on ownership; GP and each individual LP / currently and what it should be.
6) Respond to TGB's question on your activity for the partnership

@Rick19744   I interpret it as a separate SMLLC is one of the Partners (the General Partner) of a Family Partnership.

Concur, I just want more detail instead of guessing.

It is correct that the GP LLC was formed to be the General Partner. I am the owner of the LLC. I am not"going from GP to LP." I am an original LP in the partnership creation. Accountant doing taxes coded it differently... I don't know if he just didn't understand partnerships. He said he did. I am the"tax matters person" so maybe that is why he did it. He is now retired and that was 4 years ago, haven't used him since then. But I think the GP LLC could, and should, be the tax matters partner. It would still be me. The other LPs are my son and my mother.  To answer TGB's question, no I do not work for the company. The partnership and LLC were set up by a competent lawyer, but that lawyer's fees are out of our price range now. Thanks

So what I am seeing here is that all along the partnership has reflected the correct individuals as LP's, it is just that the returns have reflected you as an individual as the GP instead of the LLC as the GP.  Is that what you are saying?

Does your LLC have an EIN?
I assume that the LLC has no activity other than hold the interest in the partnership?
Who is the decision maker for the partnership?

Regarding your summary, you are correct.
To answer the second part, each entity does have an EIN. There are workers who make decisions. I ok any large capital expenditures. That's it. What's your opinion about the K1 GP designation then?

My bad, the GP LLC is technically owned by my mother. I checked the documents more carefully. Since it is a disregarded entity and doesn't file a tax return I got confused. My mother is not the tax matters partner. Is that why you're saying what the accountant did was ok for the tax return?Thanks a lot for drilling into this with me.

Ok.  So my original answer below will change somewhat due to late breaking facts as past returns appear incorrect:

1) The TMP must be a GP.  This should be changed as well.
2) My biggest concern here, based on the updated facts, is whether or not the allocation of income or loss has been correct in the past.  Your initial facts indicate that you were designated as the GP, which means you were allocated the GP's percentage instead of your Mom.  So my assumption is the past allocations have been incorrect.
3) Generally in a limited partnership the GP has a 1% interest.  If that is the case here, then if the prior allocation was incorrect as noted above, then technically amended tax returns need to be filed.
4) Amending partnership returns is not as straight forward as other returns.  Some just file a form 1065X, but that is not always correct.  Generally, form 8082 should be filed and this form will set off some bells and whistles at the IRS.  When filing this form and requesting an Administrative Adjustment Request, the IRS technically needs to respond with an approval or denial.  This process adds a level of scrutiny that generally is best to avoid, but may unfortunately be the correct avenue.
5) The form 1065 definitely needs to be corrected for 2017.
6) The decision is yours as to how you will handle past years if the allocation was incorrect.

Thanks a lot for all your help. You are knowledgeable and I appreciate it. I have paid the taxes according to my percentage, and all taxes have been properly paid as they should have been allocated. I will decide what to do from now. Again, thank you.

Welcome.

Got it.

Edit [This answer was technically correct based on original facts, however, those facts changed and so parts of this response was updated in comments above]

This will be a somewhat long response, however, I think it is important to understand the reasoning and the ultimate end result.

All limited partnerships are formed under the applicable state statutes.  States will follow either the Uniform Limited Partnership Act (ULPA) or the Revised Uniform Limited Partnership Act (RULPA).

Regardless of which Act the state follows, all limited partnerships MUST have at least one general partner that bears personal liability for partnership obligations.

So in your case, you set up an LLC owned by you, which by default is a disregarded entity under the check-the-box regulations.

Any entity who is required to file an information return with the IRS should be obtaining a form W-9 from all taxpayers.  In this case, the partnership would be requesting these from the partners.

For the GP, the W-9 instructions are not the model of clarity, but in the end, the IRS indicates it "encourages" the use of a SSN when the entity is disregarded and owned by an individual.

Having said that, it is really a moot issue who you use for the GP in your case.  This is because whether you reflect the single member LLC and its EIN or you individually and your SSN, at the end of the day:

• The K-1 gets reflected on your individual tax return
• You are still ultimately liable for all partner obligations