PLLC-professional limited liability company. Two partners, past accountant prepared form 1065, is it correct? I thought it has to file from 1020 or form 1020s. Unless it was single member, then schedule c can be used.
It may be an issue with how the LLC is or can be registered to do business in the state of registration. Some states require LLCs to be partnerships, some corporations, and still other do not specify.
Unless I was told to change the Federal or state tax return form being used, I continue to file as has been previously done.
Oh... 1120. Well the answer is like gkaiseril said, it depends upon the actual default entity classification or actual election made.
Since they have been filing a partnership tax return 1065 all you have to do is ask them if their entity is organized with the state as a LLC or partnership. In other words is the "C" in PLLC of the organization paperwork say corporation or company. If they say "company" they should file 1065 unless they have filed an election to be taxed as a corporation.
It seems pretty certain that it would be filed on a Form 1065. A PLLC would be an LLC. People like to use abbreviations like SMLLC, PLLC and PDQ instead of spelling out what they mean.
However, an LLC could elect to be taxed as a corporation by filing a Form 8832--which brings us back to square one.