IRS Name Control Calculator: Individuals, LLCs, Corporations

IRS name control calculator

Type the name exactly as it will appear on line 1 of the return or W-9, pick the entity type, and get the four-character name control the IRS will compare against its records, with the rule that produced it. Runs in your browser; nothing is sent.

Basis IRS Publication 1586 (Rev. 8-2026), part IX, and Publication 1220: the name control rules and worked examples for individuals, sole proprietors, corporations, partnerships and single-member LLCs, estates, trusts and other organizationsPrivacy runs in your browser; nothing you enter is sent or stored

Name as it will appear on line 1

Runs in your browser; nothing is sent.

Entity type

Spanish-style double surname (two unhyphenated last names: use the first)

Type a name.

The calculator applies the published rules; it cannot know what the SSA or IRS actually has on file for a number, which is what the match uses. When a pair still fails, the fix is the name on the Social Security card or the CP 575 / Letter 147C, not a better guess.

What the result means

The IRS does not match the full name on a 1099. It derives a name control, up to four characters, from the name line and compares it with the name control stored for the TIN: the Social Security Administration’s record for an SSN, the IRS business master file for an EIN. If the four characters agree, the return is accepted; if not, the payee appears on next spring’s CP2100. That is why Robert Smith, Bob Smith and R. Smith all pass (SMIT) while a sole proprietor who puts the business name on line 1 fails.

How the match works

Name line on the returnUp to 40 characters; the IRS reads the first two name lines.

Derive the name controlFour characters, by the entity-type rules.

Compare to the fileSSA’s record for an SSN; the IRS master file for an EIN.

Accepted or CP2100Same four characters: matched. Different: a notice next spring.

The rules in brief

Individuals and sole proprietors: the first four characters of the last name; prefixes and particles count (McCedar → MCCE, de la Rosa → DELA); a hyphenated surname uses the first part; the trade name never enters it. Joint payees use the primary payee’s last name (Edward & Joan Maple → MAPL).
Corporations, nonprofits, funds: the first four significant characters of the name, dropping a leading “The” when more than one word follows.
Partnerships, multi-member LLCs and single-member LLCs with their own EIN: a dba or trade name first; otherwise the first four characters of the partnership or LLC name for an online-assigned EIN, or the last name of the first partner for a paper-assigned one. Publication 1586 (Rev. 8-2026) groups single-member LLCs with partnerships for this purpose.
Estates and trusts: the decedent’s or grantor’s last name, except that an online-assigned EIN uses the first name on the line.
Political organizations: the individual’s name as it appears in the committee name (Committee to Elect Patrick Dole → PATR).

The full rules, the IRS’s own worked examples and the reasons real names fail are on the IRS name control reference page.

What it cannot tell you

The calculator applies the published rules to the name you typed. It cannot know what the SSA or the IRS actually holds for a number, and that record is what the match uses. A payee who changed their name without filing Form SS-5, or an entity whose EIN was issued under an older name, will still mismatch with a correctly derived name control. For those, the fix is the name on the Social Security card, or the CP 575 or Letter 147C for an EIN, and an IRS TIN match before filing.