Plan number (PN)
Three-digit identifier assigned by the sponsor to each plan they sponsor.
Definition
Plan number (also called PN or plan sequence number) is a three-digit ID the sponsor assigns to each retirement plan. The first 401(k) or pension plan adopted by a sponsor is generally numbered 001; the second 002, etc. Once assigned the number must not change for the life of the plan and is reported on Form 5500-EZ line 1b.
Why it matters
For IRS Form 5500-EZ, this term helps decide which records, dates, values, or review questions belong in the packet.
How the tool uses it
Solo 5500 treats this as a review signal. The user enters the facts, checks the source-linked explanation, reviews the packet, and files through the official channel when the supported case still fits.
When to check the source
Check the official source when the answer depends on eligibility, late filing relief, official correspondence, valuation, or a fact you cannot verify from your own records.
Source and review date
Last reviewed: . Use the linked source for the official wording behind this term.
Official source: IRS Form 5500-EZ filing notices