IRS TIN Matching 101: When to Use It, What It Catches, What It Doesn’t (2026 Guide)

If you’ve ever received a CP2100 notice, you already know the pain: a vendor name/TIN mismatch turns into follow-ups, documentation, and sometimes backup withholding. The frustrating part is most of these issues are preventable.

That’s what IRS TIN Matching is for.

TIN Matching helps you validate a vendor’s name + taxpayer identification number (TIN) combination before you file information returns like 1099s. It doesn’t replace collecting a W-9 it complements it.

This guide breaks down:

• when to use TIN Matching (and when not to),
• what it actually catches,
• what it doesn’t catch (so you don’t get a false sense of security),
• and a simple workflow you can adopt in AP.

What is IRS TIN Matching?

TIN Matching is an IRS e-Services tool that checks whether the payee name + TIN you have on file matches IRS records before you submit information returns.

A “TIN” can be:

• EIN (Employer Identification Number)
• SSN (Social Security Number)
• ITIN (Individual Taxpayer Identification Number)

In plain terms: TIN Matching reduces the odds you’ll file a 1099 with bad vendor data.

TIN Matching vs W-9: what’s the difference?

These get mixed up constantly, so here’s the clean separation:

W-9 (collection)

A W-9 is the vendor’s statement of:

• their legal name,
• entity type,
• TIN,
• and certification.

It’s the “source of truth” you collect from the vendor.

TIN Matching (validation)

TIN Matching is what you use to:

• validate the name/TIN combination,
• before filing 1099s,
• and reduce mismatch notices later.

Bottom line:
Collect W-9s first. Then TIN match your records before you file.

When should you use TIN Matching?

Here are the moments when it actually pays off:

1) Before 1099 season (the obvious one)

Run TIN Matching before you generate or file your 1099s. This lets you fix mismatches while you still have time.

2) When onboarding vendors you’ll likely 1099

If your business regularly pays contractors, freelancers, agencies, or vendors that could receive a 1099, it’s smart to validate early not at year-end.

3) When a vendor updates their legal name or entity

If a vendor says “We changed our name” or “We’re now an LLC,” you should treat that as a data-risk moment. Collect an updated W-9 and validate your record.

4) After you receive a CP2100/CP2100A notice (damage control)

If the IRS flags a mismatch, your priority is response and documentation. TIN Matching won’t erase that notice but it helps you prevent repeats by correcting your vendor master data.

5) After major vendor master cleanup

If you’re doing a vendor master overhaul (deduping, fixing DBAs, standardizing legal names), validating the updated records is a smart final step.

When you should NOT use TIN Matching

TIN Matching is useful, but it’s not magic. Don’t waste time using it for:

• Non-US vendors (they generally need W-8 forms, not W-9)
• Vendors you’ll never issue 1099s to (for example, many corporations or vendors paid by credit card/processors)
• Bank account verification (TIN Matching does not verify bank details)
• Address validation (it does not verify addresses)
• Entity classification compliance (it does not confirm whether the vendor is truly an S-Corp vs partnership, etc.)

Use it where it reduces real risk: name/TIN mismatch on reportable payments.

What TIN Matching catches

Most mismatches are not “fraud” they’re just messy vendor data. TIN Matching helps catch:

1) Typos and transposed digits

One digit off in an EIN is enough to trigger mismatch problems later.

2) “DBA” vs legal entity name errors

Vendors often write a business name / DBA when the IRS record is tied to a different legal name.

3) Nicknames, shortened names, or missing middle initials (for individuals)

For individuals, small name differences can matter depending on how IRS records are set.

4) Wrong TIN type used

Example: vendor gives EIN, but their payments should be tied to an individual/SSN in the way they report.

5) Stale vendor records

Vendor got married, changed business name, changed entity, or corrected their info — but your system still has the old combination.

What TIN Matching does NOT catch

This is the part people ignore then wonder why they still have problems.

TIN Matching does not:

• Verify the vendor is eligible for a specific tax classification
• Tell you whether you “should” issue a 1099
• Confirm the vendor is US vs non-US (that’s a form decision: W-9 vs W-8)
• Validate addresses (use address validation for that)
• Verify bank ownership or prevent ACH fraud
• Replace W-9 collection and certification
• Replace your CP2100/B-Notice response process

Think of it as a filter. Not a shield.

IRS TIN Matching options (Interactive vs Bulk)

The IRS generally offers two modes:

Interactive TIN Matching

Best for:

• onboarding a handful of vendors,
• spot checks,
• smaller AP teams.

Bulk TIN Matching

Best for:

• pre-1099 season validation,
• vendor master cleanup projects,
• large vendor lists.

If you’re dealing with hundreds (or thousands) of vendors, Bulk is the realistic option.

A simple “safe” workflow for AP teams

You don’t need a complicated compliance program. You need a repeatable workflow.

Step 1: Request the W-9 before the first payment

This is the easiest point to enforce compliance without drama.

Step 2: Standardize how you store the vendor name

Use a rule like:

• Legal name (exactly as on W-9) goes in the legal name field
• DBA goes in a separate DBA field (if your system has it)
• Never mix the two

Step 3: Validate the record before filing 1099s

Run TIN Matching during your pre-1099 checklist window (not the week of filing).

Step 4: Fix mismatches with a clean vendor message

Don’t accuse. Don’t ramble. Just be clear and neutral.

Example message (vendor-friendly):
“Hi, we’re updating our tax records for year-end reporting. The name/TIN combination we have doesn’t match IRS records. Can you confirm your legal name and TIN by submitting an updated W-9 using this link?”

Step 5: Keep an audit trail

If you ever get questioned internally (or in an audit), you want to show:

• what you requested,
• what the vendor submitted,
• when it was submitted,
• and what changed.

Decision tree: Do I need to run TIN Matching?

Use this as your weekly asset (turn it into a one-page graphic later):

1. Are you paying a US person/entity for reportable payments?

• No → Don’t use TIN Matching.
• Yes → continue.

2. Do you have a W-9 on file?

• No → Request W-9 before paying.
• Yes → continue.

3. Is this vendor likely to receive a 1099?

• No / unsure → Still keep W-9 clean; validate before filing season.
• Yes → continue.

4. Are you within your pre-1099 window or doing onboarding at scale?

• Yes → Run TIN Matching (bulk if many).
• No → Schedule it as part of your monthly/quarterly vendor audit.

Where GetW9 fits (without pretending it does everything)

TIN Matching is about validation. GetW9 is about getting clean, consistent W-9 data into your system so validation is actually usable.

With GetW9, teams typically use it to:

• send vendors a secure link to complete a W-9 (no PDF ping-pong),
• reduce missing fields and “unreadable scan” issues,
• save completed W-9 PDFs with a submission history,
• control who can access tax forms (role-based access),
• and (optionally) connect QuickBooks to reduce duplicate vendor entry.

If your current process involves email attachments and manual typing, you’re manufacturing mismatches. Fix the intake process first — then validation becomes easy.

Common mistakes that create name/TIN mismatches

If you do nothing else, stop these:

• Copying the vendor name from an invoice instead of the W-9
• Storing DBA in the legal name field
• Letting multiple people “edit vendor name” with no rules
• Waiting until January to request corrections
• Treating vendor master data as “admin work” instead of compliance infrastructure

FAQs

Is TIN Matching required?

Not always. But it’s a strong preventative step if you file information returns and want to reduce mismatch issues.

Does TIN Matching replace collecting a W-9?

No. TIN Matching validates the record. The W-9 is the vendor’s certification and the source document you need on file.

How often should I run TIN Matching?

At minimum: before filing 1099s.
If you have high vendor turnover: consider a monthly or quarterly vendor audit run (especially after onboarding spikes).

If I received a CP2100 notice, what should I do first?

Follow the CP2100/B-Notice process. Don’t improvise. Your goal is compliance, documentation, and starting/stopping backup withholding when required.

Will TIN Matching catch vendor fraud?

Not reliably. Fraud prevention requires controls like bank-change verification, segregation of duties, and secure intake — separate topic.

Takeaway

TIN Matching is not a “nice-to-have” for AP teams who file 1099s. It’s a prevention tool that helps you:

• reduce name/TIN mismatch headaches,
• avoid unnecessary vendor follow-ups,
• and keep compliance from turning into a January fire drill.

The winning combo is simple:
Collect clean W-9s → enforce naming rules → validate before filing → keep an audit trail.