Here is a mistake that does not show up anywhere until it is expensive. You pay a contractor. Their W-9 has a TIN that does not match what the IRS has on file. Nothing happens for ten months. Then a CP2100 notice arrives, you are in the highest penalty tier because it landed after August 1, and a single wrong number is now a several-hundred-dollar penalty plus a backup-withholding obligation you have to manage by hand.
TinCheck exists to kill that mistake at the source. It verifies a name and TIN against live IRS records before you file, so the wrong number never enters your books. This review covers what it actually does, what it costs, how it stacks up against the free IRS option everyone forgets exists, and whether a startup should bother. Short version up front: for any company paying 1099 contractors, it is one of the highest-return compliance tools you can buy, and the first check is free.
What TinCheck Is
TinCheck is the self-serve, real-time tax-identity verification service from Sovos. Sovos is not a small player. It is one of the largest dedicated tax-compliance companies in the world, running tax determination and information reporting for a large share of the Fortune 500. TinCheck is the front door to that same verification infrastructure, priced and packaged for small teams instead of enterprise procurement.
The core function: you submit a payee's legal name and taxpayer identification number, and TinCheck matches the pair against IRS records in real time. You get back a clear result. Match, no match, or a specific mismatch reason. That one result is the difference between a clean 1099 season and a stack of IRS B-Notices.
What It Actually Checks
A common misread is that TinCheck only does TIN matching. It does more, and the extra coverage is most of the value.
- IRS TIN and Name matching, plus EIN Name Lookup and IRS Exempt Organizations checks
- OFAC and SDN sanctions screening, US state watch lists, and global sanctions lists (UN, EU, Canadian, Ukraine-Russia related)
- Death Master File screening to catch SSNs tied to deceased individuals
- GIIN verification for FATCA-relevant payees
- USPS Address Validation so the address on the form is deliverable
For a startup, that means one check does two compliance jobs at once. It stops a bad 1099 before it is filed, and it stops you from paying a sanctioned or flagged party in the first place. The sanctions piece matters more than founders think, and there is a section on it below.
How It Works in Practice
The flow is deliberately boring, which is the point. A new contractor signs. Before the first invoice is paid, you run their legal name and TIN through TinCheck. The result comes back in real time. If it matches, you move on with certainty. If it does not, you fix the W-9 now, while the contractor is still in onboarding and happy to respond, instead of nine months later when they have no incentive to help and the IRS clock is running.
That timing is the entire product thesis. The check is cheap and early. The IRS notice is expensive and late. TinCheck moves the catch to the moment it costs you nothing.
The Penalty Math, Current for 2026
This is why the tool has real ROI rather than theoretical value. The numbers below are the actual 2026 IRS figures.
File a 1099 with a name/TIN combination that does not match IRS records and you are exposed under two separate code sections at once. IRC Section 6721 penalizes the incorrect return filed with the IRS. IRC Section 6722 penalizes the incorrect statement furnished to the payee. The same wrong TIN triggers both. They stack.
Per-form amounts for 2026:
- $60 per form if corrected within 30 days of the deadline
- $130 per form if corrected after 30 days but by August 1
- $340 per form if corrected after August 1 or not at all
Name/TIN mismatches are surfaced by IRS CP2100 and CP2100A notices, the "B-Notices." Those frequently arrive after August 1, which pushes most TIN-mismatch penalties into the top tier. Because 6721 and 6722 both apply, the realistic exposure on one uncorrected wrong TIN is closer to $680 per payee, not $340. The de minimis safe harbor does not help. It only covers small dollar-amount errors. A wrong TIN is a non-amount error and is explicitly not excused.
There is a second cost most founders never price in. A B-Notice obligates you to start 24% backup withholding on that payee's future payments until the TIN is corrected. That means withheld payments, awkward contractor conversations, and a manual tracking burden your finance stack was not built for.
Run it across a startup paying 30 contractors. If five TINs are wrong, common when payees self-report their own data, that is roughly $3,400 in stacked penalties before you count remediation time and the withholding mess. Against that, a tool whose first check is free and whose plans start at $19.95/month is not a close call.
The Sanctions Risk Nobody Models
The penalty is the obvious cost. The OFAC exposure is the one that should actually scare a founder.
OFAC enforcement is strict liability. You do not need intent. You do not need knowledge. If you pay a name on the Specially Designated Nationals list, the violation is the payment itself, and civil penalties run into the tens or hundreds of thousands of dollars. For a seed-stage company, a single sanctions hit is not a line item. It is an existential event with legal fees attached.
Founders assume this only applies to banks. It does not. The moment you pay an international contractor or a vendor whose ownership you cannot fully see, OFAC rules apply to that payment. TinCheck folds sanctions screening into the same check that verifies the TIN. The verification you run to dodge a $340 IRS penalty also screens against the lists that carry six-figure exposure. That bundling is the strongest argument for running every payee through it, not just the ones you are unsure about.
Pricing
The offer through SaaSOffers: your first real-time check is free, with no payment method required. After that, monthly plans start at $19.95/month with volume discounts as your check count rises. It is pay-as-you-go. No enterprise contract, no per-seat licensing. You pay for checks, not for software.
Verify the current numbers on the TinCheck site before relying on them, since pricing can change, but the structure is built for small teams. The comparison that matters is not "$19.95 vs free." It is "$19.95/month vs $680 per missed TIN plus backup withholding." One avoided mismatch pays for years of the subscription.
TinCheck vs the Alternatives
TinCheck vs the free IRS TIN Matching portal. The IRS e-Services TIN Matching program is genuinely free, and most founders forget it exists. The catch: it is built for established filers, not startups. It is bulk and batch-oriented, requires an application tied to prior filing history, has no real-time single-check flow that fits onboarding, and returns only a terse match code with no sanctions screening, no address validation, no DMF check. If you are a high-volume, established payer who can wait on batch results and only needs the match code, the IRS portal wins on price. For a startup onboarding contractors year-round, TinCheck wins on speed, usability, and scope.
TinCheck vs filing platforms (Tax1099 and similar). Filing tools bundle TIN matching as a feature of a year-end e-filing product. That is fine if you have already committed to one for filing. TinCheck wins when you want verification decoupled from filing and run at onboarding rather than in January, with sanctions and address checks included. It is a verification tool, not a filing tool, and that focus is the value.
TinCheck vs doing nothing. This is the real comparison, because most startups do nothing until a notice arrives. The expected cost of nothing is per-form penalties under 6721 and 6722, backup-withholding obligations, and remediation hours. TinCheck's cost is one free check, then dollars per verification. The expected-value math is not close.
Who Should Use It
Use TinCheck if you pay 1099 contractors, freelancers, or agencies, especially ones who self-reported their tax data. Use it if you onboard vendors year-round and want verification at signup instead of at filing. Use it if you pay international or higher-risk parties and need OFAC screening anyway. And definitely use it if you have ever received a CP2100 B-Notice and do not want a second one.
You can skip it if you have zero contractor or vendor payments, or if every payee is run through a payroll or contractor platform that already performs IRS TIN matching for that payee type. Check whether your platform actually does this. Many do not for all payee types, and the gap is where the penalties live.
The Verdict
TinCheck is a narrow tool that does one job with disproportionate downside protection. It is not exciting software. It is insurance with a free first check and a sub-$20 entry price, backed by the most credible name in tax compliance. For a startup paying contractors, the question is not really whether TinCheck is worth $19.95 a month. It is whether you can afford to find out the hard way that a payee's TIN was wrong. Run the free check on your single riskiest payee today and let the result decide for you.
Claim the free TinCheck verification on SaaSOffers
Frequently Asked Questions
The Bottom Line
A wrong contractor TIN is silent for months and then expensive all at once. It does not appear in a dashboard. It appears as an IRS notice, a stacked per-form penalty, and a backup-withholding headache during your worst week of the year. TinCheck, backed by Sovos, removes the error at the source with a real-time check before the payment and before the filing. The first one is free, so the cost of finding out whether your riskiest payee is a problem is zero.
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Disclosure: SaaSOffers may earn a commission if you start a paid TinCheck plan through our link, at no extra cost to you. We feature it because the penalty math is real and the first check is genuinely free, and we list the free IRS alternative above so you can decide honestly.
Software engineer and product builder with 13+ years of experience across software engineering, product development, and startup operations. Built SaaSOffers to make every startup deal discoverable and verified for founders worldwide.
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