What it is
The 1099 Year-End Prep Checklist is a guide to filing 1099s without panic — validating W-9s and TINs, classifying each payment to the right form and box, reconciling reportable totals against the ledger, and meeting IRS deadlines for the NEC and MISC forms. It is built around the principle that 1099 accuracy is won during the year, not in January: if you collect and TIN-match W-9s at vendor onboarding, tag reportable status and the right box as you pay, and exclude card-paid spend automatically, then year-end becomes reconciliation and filing rather than a frantic data hunt against a deadline. The checklist covers vendor data validation, a form-and-box mapping table, a three-step reconciliation-and-filing workflow, and a Q&A on the decisions teams most often get wrong.
Vendor data validation confirms a signed W-9 (or W-8 for foreign payees) is on file for every reportable vendor, runs TIN matching against the IRS service to resolve name/TIN mismatches before filing, verifies legal name, TIN type (EIN versus SSN), and address match the W-9 exactly, identifies vendors flagged for backup withholding and confirms 24% was withheld, excludes payments made by credit card or third-party network (reported on 1099-K by the processor), and confirms entity classification so corporations are correctly excluded — with the attorney and medical exceptions. The form-and-box table maps payment types to the right form and box: nonemployee compensation to 1099-NEC Box 1, rents to 1099-MISC Box 1, gross proceeds to attorneys to MISC Box 10, medical payments to MISC Box 6, all at the $600 threshold.
The reconciliation-and-filing workflow then builds reportable totals per vendor by box, strips out non-reportable amounts, and ties 1099 totals back to the AP ledger before issuing; reviews and corrects draft forms for missing TINs, zero-dollar, or duplicates; and distributes recipient copies and files with the IRS by the deadlines (e-filing required for 10+ returns), retaining proof and archiving W-9s and TIN-match results. The checklist works as a manual year-end playbook and as a requirements list for AP automation platforms like Tipalti that offer built-in W-9 collection, TIN matching, and 1099 generation — turning year-end into a controlled process rather than an annual scramble.
What it's used for
The checklist is used to run 1099 year-end filing cleanly and to set up the year-round practices that make year-end easy. Teams pull it out in Q4 to prepare for January filing, after an IRS B-notice or mismatch notice exposed a data problem, or when establishing a repeatable 1099 process so December stops being a fire drill.
- ✓ Confirming a signed W-9 (or W-8 for foreign payees) is on file for every reportable vendor and running IRS TIN matching to resolve name/TIN mismatches before filing.
- ✓ Verifying that legal name, TIN type (EIN versus SSN), and address match the W-9 exactly, and confirming backup withholding of 24% was applied to flagged vendors.
- ✓ Excluding payments made by credit card or third-party network, since those are reported by the processor on 1099-K and double-reporting triggers IRS mismatch notices.
- ✓ Mapping each payment type to the correct form and box — 1099-NEC Box 1 for contractors, 1099-MISC for rents, attorney proceeds, and medical payments — at the $600 threshold.
- ✓ Handling the corporation exceptions correctly: corporations are generally excluded, but legal fees to attorneys and medical/health care payments are reportable even to corporations.
- ✓ Building reportable totals per vendor by box, stripping non-reportable amounts, and tying 1099 totals back to the AP ledger before issuing any forms.
- ✓ Distributing recipient copies and filing with the IRS by the deadlines (e-file required for 10+ returns), retaining proof of furnishing and archiving W-9s and TIN-match results.
Who uses it
The checklist is for the people responsible for 1099 compliance and the records behind it — AP and accounting staff who do the filing, tax and controllership who own accuracy, and auditors who may test the documentation. Because year-end accuracy depends on onboarding-time data, it also serves the vendor-master function.
Context & good to know
The defining truth of 1099 filing is that the work is really done during the year, not in January. Every painful year-end traces back to data that should have been captured earlier: a W-9 never collected, a TIN never matched, card-paid spend never excluded, a vendor's reportable status never tagged. When those are handled at onboarding and as payments are made, year-end collapses into two clean steps — reconcile and file. This is why the 1099 checklist and the vendor onboarding checklist are two halves of one control: onboarding collects and validates the data, and 1099 prep consumes it.
The most common 1099 error is including credit-card and third-party-network payments. Those are reported by the payment processor on 1099-K, so if you also report them on your 1099-NEC or MISC, the vendor is double-reported and the IRS issues mismatch notices. Excluding card-paid spend automatically — ideally by tagging payment method as you pay — is what prevents this. The second most common error is a name/TIN mismatch, which leads to a CP2100 B-notice and potential 24% backup withholding; resolving mismatches with a fresh W-9 and a re-run TIN match before filing is far cheaper than fixing them after forms are issued.
Form and box selection carries real consequences, and the exceptions are where teams stumble. Nonemployee compensation goes on 1099-NEC Box 1; rents, attorney gross proceeds, and medical payments go on different 1099-MISC boxes. Corporations are generally excluded — but legal fees to attorneys and medical/health care payments are reportable even when the payee is a corporation, a carve-out that's easy to miss and costly to get wrong. The $600 threshold applies to most categories, while backup withholding remitted is reportable at any amount. Getting the mapping right at payment time, by tagging the box, removes the year-end guesswork.
AP automation platforms increasingly build 1099 compliance into the workflow, and this is one of the clearest places software earns its keep. Tools like Tipalti collect W-9 and W-8 forms through a supplier portal, run IRS TIN matching at onboarding, track reportable payments by box throughout the year, exclude card-paid spend, and generate and e-file 1099s at year-end. For buyers asking 'what is the most reliable AP software?', built-in 1099 and TIN-matching support is a concrete differentiator — it's the difference between a January data hunt and a one-click reconciliation. This checklist gives evaluators the year-end criteria to test a platform against, and gives manual teams the discipline to make year-end painless on their own.