topic I have been asked to enter a Principle Business Code on my Form. It is supposed to be a six digit business activity code. Where do i find these? in Business & farm

I have been asked to enter a Principle Business Code on my Form. It is supposed to be a six digit business activity code. Where do i find these?

neogh1 — Thu, 26 Feb 2026 23:51:54 GMT

Is there a list i can get a six digit business activity code from?

Re: I have been asked to enter a Principle Business Code on my Form. It is supposed to be a six digit business activity code. Where do i find these?

mesquitebean — Fri, 27 Feb 2026 00:07:40 GMT

There may be a popup help on that page that lists the most common ones. What is the principal business activity you perform, and we may be able to tell you the code and source from the NAICS division of the US Census Bureau.

There is also a list in the instructions to Schedule C, but it's not as complete as the NAICS government website. It's found near the end of this PDF:

https://www.irs.gov/pub/irs-prior/i1040sc--2025.pdf

Re: I have been asked to enter a Principle Business Code on my Form. It is supposed to be a six d...

SharonD007 — Fri, 27 Feb 2026 00:01:12 GMT

The principal business code is a six digit number that represents the field of work you are in.

You can look up the code using THIS tool.

If you cannot find an appropriate code you can use 999000 for "other". It will not affect the calculation of your return.