Most 1099 penalties are not the result of bad intentions. They come from the same preventable mistakes that businesses, accountants, and bookkeepers make every filing season: a missing W-9, the wrong form type, a TIN that does not match IRS records, or a paper return filed when eFile is required. Each of these triggers the same penalty structure under IRC sections 6721 and 6722, applied per form.
The good news is that every mistake on this list is fixable, and most are preventable with the right process. This guide covers the seven most common 1099 filing errors and exactly what to do about each one.
Mistake 1: Not Collecting W-9s Before the First Payment
The most common upstream cause of 1099 errors is waiting until January to collect W-9s from vendors and contractors who were paid throughout the year. By that point, vendors have been paid and have little incentive to respond quickly. Missing or unverifiable TINs create two immediate compliance problems. The 1099 cannot be filed accurately, and backup withholding at 24% should have been applied to payments made without a valid TIN on file.
The IRS standard is straightforward; collect the W-9 before the first reportable payment, not after. A vendor who refuses to provide a W-9 triggers an obligation to begin backup withholding on all future payments immediately. That withheld amount must be deposited with the IRS and reported on Form 945 at year-end.
The fix: Make W-9 collection a necessary step in your vendor onboarding process. No W-9 means no payment. This single control eliminates the January scramble and creates the documentation baseline needed for accurate TIN matching before filing.
Mistake 2: TIN Mismatches and Name/TIN Combination Errors
Submitting a 1099 with a TIN that does not match the name in IRS records is one of the most common and consequential errors. When a name/TIN combination fails the IRS match, the IRS issues a CP2100 or CP2100A B-Notice to the payer.
A B-Notice requires you to solicit a corrected W-9 from the affected vendor. If the mismatch is not resolved, you must begin backup withholding at 24% on all future payments to that vendor. A second B-Notice for the same vendor within three years triggers immediate withholding, which stops only after the IRS confirms the TIN is correct.
The most common causes of name/TIN mismatches:
- The payee uses a DBA (doing business as) name rather than the legal name on file with the IRS
- A single-member LLC owner provides the LLC name but uses a personal SSN, or the reverse
- A digit in the TIN was transposed during data entry
- The payee’s legal name changed after marriage or entity restructuring, and the W-9 was never updated
The fix: Run bulk TIN matching against IRS records before the January filing window closes. Catching mismatches early means corrections cost $60 per form rather than $340 per form.
eFileMyForms, powered by Sovos, includes built-in TIN verification as part of the filing process. Businesses also do not need to obtain a separate Transmitter Control Code (TCC) from the IRS to file. You can submit directly through eFileMyForms.
Mistake 3: Misclassifying LLC Vendors
LLCs are the most common source of form-filing confusion because the IRS does not recognize them as a tax classification. Whether a 1099 is required depends entirely on how the LLC is taxed, and that information comes only from the vendor’s W-9.
| LLC Tax Classification | W-9 Box 3 Indication | 1099-NEC Required (Services)? | Notes |
| Single-member LLC (disregarded entity) | Individual / Sole proprietor | Yes, if $600+ paid for services | $2,000 threshold applies from tax year 2026 (forms due 2027) |
| Multi-member LLC (taxed as partnership) | Partnership | Yes, if $600+ paid for services | |
| LLC electing S corporation status | S Corporation | Generally no | Exception: attorney fees, medical payments |
| LLC electing C corporation status | C Corporation | Generally no | Exception: attorney fees, medical payments |
One important exception is payments to attorneys and law firms. The corporate exemption does not apply to legal services, so attorneys and law firms must generally receive a Form 1099, even if they are organized as an S corporation or C corporation. Payments of $600 or more for legal services are typically reported on Form 1099-NEC, while certain settlment-related gross proceeds paid to attorneys are reported on Form 1099-MISC.
The fix: check the entity type on each vendor’s W-9 before filing. Do not default to filing a 1099-NEC for every vendor without confirming their tax classification first.
Mistake 4: Using the Wrong Form Type
The 1099 series includes more than a dozen distinct forms. Using the wrong one puts income in the wrong category and requires a corrected filing. The most frequent errors:
1099-NEC vs. 1099-MISC confusion
Since the IRS reinstated Form 1099-NEC for nonemployee compensation in 2020, payments for contractor services must go on the NEC, not the MISC. Rents, royalties, prizes, and most non-service income go on the MISC.
Medical payments and attorney gross proceeds
Payments to physicians, health facilities, or medical providers of $600 or more go on 1099-MISC Box 6, not the NEC. Gross proceeds paid to an attorney (including settlements) go on 1099-MISC Box 10, even if the attorney is incorporated. Fees for legal services go on the NEC.
Using a prior-year form
When paper filing, the IRS requires the current year’s official Copy A. A printout of a prior-year form downloaded from the internet will be rejected, and a late-filing penalty accrues from the original deadline even if you believed you had submitted on time.
Mistake 5: Paper Filing When eFile Is Required
Since January 1, 2024, businesses that file 10 or more total information returns in a calendar year must eFile. The 10-form threshold is calculated in aggregate across all return types, W-2s, and all 1099 variants combined. A business filing three W-2s and eight 1099-NECs has 11 total information returns and must eFile all of them.
Paper filing above this threshold generates a separate penalty under Treasury Regulation 301.6011-2, on top of any accuracy or timing penalties. This applies even if the returns are filed on time and error-free.
To request a hardship waiver, submit Form 8508 before the filing deadline. Without an approved waiver, paper filing is non-compliant.
Mistake 6: Reporting Non-Reportable Payment Amounts
Overstating or understating payment amounts creates mismatches that can trigger notices to both you and the recipient. The three most common amount errors:
- Including expense reimbursements: Reimbursements made under an accountable plan are generally not reportable income. Lumping them into the 1099 total overstates income and can generate a tax discrepancy notice for the recipient.
- Counting credit card and payment platform payments: Payments processed through credit cards or third-party networks like PayPal are reportable by the payment processor on Form 1099-K, not by your business on the 1099-NEC. Filing both results in double reporting of the same income.
- Applying the wrong threshold year: The 1099-NEC threshold for tax year 2026 filings (forms due 2027) is $2000 per vendor.
Mistake 7: Missing the Recipient Copy Deadline
The obligation to furnish a copy to the recipient is separate from the obligation to file with the IRS. Both carry independent penalty exposure under IRC 6721 (IRS filing) and IRC 6722 (recipient copy), at the same per-form tier amounts.
For 1099-NEC, both the IRS filing and the recipient copy share the same January 31 deadline. For 1099-MISC and most other forms, the recipient copy is due January 31 while the IRS eFile deadline extends to March 31.
A common mistake: Businesses treat January 31 as only the recipient copy deadline and March 31 as the universal eFile deadline. That logic does not apply to the 1099-NEC. The IRS filing deadline for the NEC is January 31, with no extended eFile window.
The Pre-Filing Checklist That Prevents Most of These Errors
Most 1099 mistakes are data quality problems, not filing problems. They originate in the vendor onboarding process and surface at year-end. Running this pre-filing sweep before January eliminates the majority of them:
- Q4: Collect and verify all W-9s. No W-9 means no payment.
- Q4: Run TIN matching against IRS records for every active vendor.
- Q4: Confirm each LLC vendor’s tax classification from the W-9 and map to the correct form type.
- January: Reconcile vendor payment totals against your records, excluding credit card payments and reimbursements.
- January: Count your total information returns across all form types. If 10 or more, eFile is required.
- Filing: Track the recipient copy deadline separately by form type — January 31 for 1099-NEC and 1099-MISC recipient copies.
- Post-filing: Monitor for B-Notices. File corrections immediately. Document every solicitation attempt.
File with Confidence Before the Deadline
The seven mistakes covered here account for the majority of 1099 penalty notices the IRS issues each year. Every one of them is preventable. The cost of a pre-filing process is always lower than the cost of penalties, corrections, and notice responses after the fact.
Start your W-9 collection in Q4, verify TINs before January, and use a validated eFile platform to catch errors before submission. If something does go wrong after filing, correct it immediately; the penalty tier resets with every week of delay.
Ready to file? Create an account with eFileMyForms and eFile your 1099s with built-in validation, state filing, and step-by-step correction support.
Frequently Asked Questions
What is the penalty for filing a 1099 with the wrong TIN?
A TIN mismatch is an information return error under IRC section 6721. The penalty depends on how quickly the error is corrected: $60 per form if corrected within 30 days of the original deadline, $130 per form through August 1, and $340 per form after August 1. The same tier structure applies to the recipient copy failure under IRC section 6722. Correcting as soon as the error is discovered is always the least costly path.
Do I need to file a 1099 for an LLC taxed as an S corporation?
Generally no, for service payments. S corporation vendors are exempt from 1099-NEC reporting for business services. The exception is attorney fees and gross legal settlement proceeds, which require a 1099-MISC regardless of the recipient’s corporate status. Always request a completed W-9 to confirm the LLC’s tax classification before making the filing determination.
Is there a penalty for paper filing when eFile is required?
Yes. Filing on paper when your aggregate information return count exceeds 10 generates a penalty under Treasury Regulation 301.6011-2, separate from any accuracy or timing penalties. This applies even if the paper forms are filed on time and contain no errors. Submit Form 8508 before the filing deadline to request a hardship waiver if eFile is not feasible.
What should I do if a vendor refuses to provide a W-9?
Begin backup withholding at 24% on all reportable payments to that vendor immediately. Deposit the withheld amounts with the IRS on your regular deposit schedule and report the total on Form 945 at year-end. File the 1099 at year-end using the information you have, noting the backup withholding in Box 4. Document every W-9 solicitation attempt with timestamps; this documentation is the basis of a reasonable cause defense if the IRS assesses a penalty.