TIN compliance for construction and contractors

What's different here

• Subs arrive before their paperwork. A vendor record built from a first invoice carries whatever name and TIN the sub typed, and the first check is often the IRS CP2100.
• Labor and materials share an invoice. Materials used in a service are treated differently from merchandise bought on its own, and equipment rented with an operator is split between two forms.
• Entity type decides the form. Sole proprietors and many LLCs get a 1099-NEC; corporations generally do not. The W-9 tells you which.
• Classification is a live question. The IRS uses construction examples in its own worker classification guidance.
• Some states take a cut first. California, New Jersey, Nebraska and Rhode Island can require you to withhold from, or hold back part of, a contractor’s pay.
• Federal work adds a layer. A contractor paid by a federal agency is reported even as a corporation, and its federal payments can be levied for its own unpaid tax.

Which payments go on which form

The threshold. For 2026 payments, Form 1099-NEC is filed for each person paid at least $2,000 for services by a non-employee. The IRS says the threshold for tax years beginning after 2025 is $2,000 and “may be adjusted for inflation beginning in calendar year 2027” (Instructions for Forms 1099-MISC and 1099-NEC, Rev. December 2026). See the Form 1099-NEC page.

Labor and materials. The instructions list as nonemployee compensation “Payment for services, including payment for parts or materials used to perform the services if supplying the parts or materials was incidental to providing the service.” The exceptions list includes “Payments for merchandise, telegrams, telephone, freight, storage, and similar items” (also Treas. Reg. 1.6041-3(c)). So a drywall sub’s invoice with labor and materials lines is usually one 1099-NEC amount, while a check to the supply house for the board is not reportable.

Equipment. The rents instructions use a bulldozer as their machine rental example and say: “If the machine rental is part of a contract that includes both the use of the machine and the operator, prorate the rental between the rent of the machine (report that in box 1) and the operator’s charge (report that on Form 1099-NEC in box 1a).”

Corporations. Payments to a corporation, including an LLC taxed as a C or S corporation, generally need no 1099-NEC or 1099-MISC. Two exceptions show up on job sites: “The exemption from reporting payments made to corporations does not apply to payments for legal services,” and medical and health care payments to corporations go in box 6 of Form 1099-MISC (Treas. Reg. 1.6041-3(p)). The LLC W-9 name guide covers reading an LLC’s W-9.

Setting up a sub from an invoice or a call

The reasonable cause rules do not require a W-9 handed over in person. Treas. Reg. 301.6724-1Treas. Reg. 301.6724-1Treasury regulations, Cornell LII requires an initial solicitation for the TIN when the account (which includes a relationship or transaction) is opened, and says: “If the account is opened by mail, telephone, or other electronic means, the TIN may be requested through such communications” (Treas. Reg. 301.6724-1(e), (f)). IRS Publication 1281 adds that outside interest, dividends and broker transactions, “the payee may furnish/provide the TIN in any manner” (Pub. 1281). A signed W-9 is still the best record.

No TIN. Pub. 1281 says to a payer whose payee refuses or neglects to give one: “Begin backup withholding immediately on any reportable payments.” The rate is 24 percent (IRS, Backup withholding). The regulation also requires a first annual solicitation by December 31 of the year the account was opened (January 31 for a December account) and a second the next year. See the solicitation guide.

Wrong TIN. A mismatched name/TIN pair comes back on a CP2100 or CP2100A. Pub. 1281 says to send the first B-Notice within 15 business days of the notice date or the date you received it, whichever is later, and to begin backup withholding no later than 30 business days after receiving the notice. The CP2100 and B-Notice guide walks through it; withholding is reported on Form 945.

To stay out of that cycle, check the pair first. The W-9 instructions describe IRS TIN Matching as letting a payor that must file information returns match name and TIN combinations with IRS records before filing (W-9 requester instructions). A sub that fails can fix its W-9 while it still wants to be paid.

Subcontractor or employee

This page describes the rules; it does not decide anyone’s status. The IRS weighs behavioral control, financial control and the type of relationship, and says “The keys are to look at the entire relationship and consider the extent of the right to direct and control the worker” (IRS, Independent contractor or employee).

Publication 15-A (2026) has five Building and Construction Industry examples. A tile setter working full time at a corporation’s sites, in the order it sets, with its materials, frequent inspections and piecework pay, is an employee. A licensed roofer with a signed flat-fee contract, insurance in the business’s name, its own employees and responsibility for repairs is an independent contractor. For a ruling on a specific worker: “If you want the IRS to determine whether or not a worker is an employee, file Form SS-8 with the IRS” (Pub. 15-A).

The 1099 matters here too: “To qualify for relief under section 530, employers must file Form 1099-NEC.” See the worker classification guide, the section 530 guide and when a worker files Form SS-8.

State contractor withholding

A matched TIN does not stop these rules. Residency, a registration or a state certificate does, so keep those documents next to the W-9. The 50-state withholding table has the full list.

California. “Withholding agents are required to withhold 7% on payments or distributions to nonresident payees when the total payments or distributions of CA source income exceeds $1,500 for the calendar year.” The FTB lists construction by independent contractors among the covered services, and reporting is on Forms 592, 592-V and 592-B (FTB, Withholding on nonresidents, updated 02/23/2026).

New Jersey. A payer for construction services (capital improvements or repairs) “must obtain proof of the contractor’s New Jersey registration or withhold 7% of the amount paid for services as Income Tax withheld.” The NJ-WT guide tells the payer to issue a Form 1099-MISC showing the amount withheld (NJ-WT, September 2025); federally, nonemployee compensation still goes on Form 1099-NEC.

Nebraska. A contractor doing business in Nebraska that pays any contractor or non-employee for construction services there withholds 5 percent unless an exception applies, the main one being that the payee is in the state contractor database (Neb. Rev. Stat. 77-2753(3)). The statute is not limited to nonresidents.

Rhode Island. Anyone doing business with a nonresident contractor “shall withhold payment of an amount of three percent (3%) of the contract price” until 30 days after the contractor finishes and asks for an audit. A temporary office at the construction site is not a regular place of business (R.I. Gen. Laws 44-1-6). The Division of Taxation applies the rule to anyone “awarding a construction contract in Rhode Island to a Nonresident Contractor” (RI Division of Taxation, Nonresident Contractor; 280-RICR-20-70-54).

Paying for someone else: lenders, owners, joint checks

A person paying on behalf of another is the payor if it performs management or oversight functions or has a significant economic interest in the payment, such as one a mechanic’s lien would compromise. The instructions’ example is a construction lender that approves draws and pays contractors from a project account. Someone who only writes checks at another’s direction is not the payor. When two parties qualify, “the person obligated to report the payment is the person closest in the chain to the payee,” unless they agree in writing otherwise (Treas. Reg. 1.6041-1(e)).

Neither the instructions nor the regulation addresses joint checks payable to a sub and its supplier, and this page does not answer that case. The rules above turn on who oversees the payment and who holds the interest in it, not on whose name is on the check.

Federal contracts and the levy program

Federal executive agencies file Form 8596 to report the contracts they enter into (Form 8596 instructions). Their payments for services are reported on 1099-NEC even to a corporation, and the W-9 instructions list those payments among corporate payments not exempt from backup withholding (W-9 requester instructions).

The IRS Federal Payment Levy Program can levy federal payments to a contractor or vendor for its own overdue taxes. For a federal contractor the levy may go out without a final notice first, and some contract and vendor payments can be reduced by 100 percent or the exact amount owed (IRS, Federal Payment Levy Program). The Form 8596 guide explains the federal contractor flag, and a levy on a vendor you paid covers a levy on one of your subs.

Controls for a contractor’s vendor file

• No vendor record from an invoice alone. Ask for the W-9 when the sub is engaged, through the same channel the job came in.
• Match before the first payment. Run the name and TIN through IRS TIN Matching at setup, not after the CP2100.
• Code the invoice, not just the vendor. Separate codes for services, incidental materials, bare equipment rent and operated equipment split the year-end file correctly.
• Override the corporate exemption for law firms and medical providers.
• Store state documents with the TIN, with dates: New Jersey BRC, Nebraska database check, California residency, Rhode Island certificates.
• Treat a missing TIN as a withholding event and calendar the annual solicitations.
• Screen the business, not just the number. Add sanctions screening and vendor existence checks. A nonresident alien sub gives a W-8 and goes on Form 1042-S; see the foreign vendors guide.

A worked example: the subs set up from invoices

A general contractor files 240 Forms 1099-NEC for tax year 2026. Sixty of its subs were set up in a hurry from a first invoice that carried no TIN, and those 60 returns go in with the TIN blank. Accounts payable kept paying all 60 through the year with no backup withholding.

The Notice 972CG proposes penalties on the 60 returns at $340 each, $20,400, and the same again under section 6722 for the payee statements, $40,800 in all.

The response that works is the solicitation record. For 35 of the subs, the setup notes show the TIN was requested on the phone call that opened the account, which the regulation allows, and the first annual solicitation went out by December 31. Under Reg. 301.6724-1 that is reasonable cause for those 35. The other 25 have no record, so the contractor pays 25 returns at $340, $8,500, and the same again under section 6722, $17,000. The record does not cure the missed withholding: Pub. 1281 says to begin backup withholding immediately when a payee does not give a TIN.

The controls above would have prevented it. Build no vendor record from an invoice alone, send the W-9 solicitation through the same channel the job came in, and treat a missing TIN as a withholding event, with the 24 percent deposited and reported on Form 945.

Questions this sector asks