Review the costliest possible mistakes first, not the most warnings. We adjust potential costs using assumptions about each vendor’s business type. The result is a review priority, not a tax bill or a measured chance of an error. A low or zero estimate is not an all-clear: warnings still need review, and tax reporting may still be required.
See the calculation and its limits
For vendors paid at least $2,000, the model starts with 24% of payments as potential tax withholding, then adds $310 as a potential penalty if the tax number is missing or incorrectly formatted. These are calculation assumptions, not a determination that either amount is owed.
We use a fixed share of that amount: 15% for apparent corporations that are not limited liability companies; 100% for apparent limited liability companies, sole owners, or businesses using a trading name; 85% for other vendors with a correctly formatted tax number; otherwise 50%. These weights use name and business-type clues, not verified tax status.
Below $2,000, this model estimates no cost. A low or zero estimate does not clear warnings or prove that no tax reporting is required. Confirm the vendor’s details and current rules with your tax adviser before acting.
Why this estimate?
Higher estimates appear first so you can review the costliest potential mistakes first, not just the most warnings.
$51,900 paid × 24% in taxes that might need to be withheld from payments = $12,456.
+ $310 potential tax form penalty because the tax number is missing or incorrectly formatted.
We use 100% of these potential costs based on clues in the contractor’s name and business type: ($12,456 + $310) × 100% = $12,766 review estimate.
This percentage is an assumption, not verified tax status or a measured chance of an error. The estimate helps decide what to review first; it is not a tax bill. Confirm the details with your tax adviser before acting.
Tax-rule references used in this calculation
Potential tax withholding: IRC §3406. Potential tax form penalty: IRC §6721; Rev. Proc. 2024-40.
Why this estimate?
Higher estimates appear first so you can review the costliest potential mistakes first, not just the most warnings.
$14,250 paid × 24% in taxes that might need to be withheld from payments = $3,420.
We use 100% of these potential costs based on clues in the contractor’s name and business type: ($3,420 + $0) × 100% = $3,420 review estimate.
This percentage is an assumption, not verified tax status or a measured chance of an error. The estimate helps decide what to review first; it is not a tax bill. Confirm the details with your tax adviser before acting.
Tax-rule references used in this calculation
Potential tax withholding: IRC §3406.
Why this estimate?
Higher estimates appear first so you can review the costliest potential mistakes first, not just the most warnings.
$8,600 paid × 24% in taxes that might need to be withheld from payments = $2,064.
+ $310 potential tax form penalty because the tax number is missing or incorrectly formatted.
We use 100% of these potential costs based on clues in the contractor’s name and business type: ($2,064 + $310) × 100% = $2,374 review estimate.
This percentage is an assumption, not verified tax status or a measured chance of an error. The estimate helps decide what to review first; it is not a tax bill. Confirm the details with your tax adviser before acting.
Tax-rule references used in this calculation
Potential tax withholding: IRC §3406. Potential tax form penalty: IRC §6721; Rev. Proc. 2024-40.
Why this estimate?
Higher estimates appear first so you can review the costliest potential mistakes first, not just the most warnings.
$2,140 paid × 24% in taxes that might need to be withheld from payments = $514.
+ $310 potential tax form penalty because the tax number is missing or incorrectly formatted.
We use 100% of these potential costs based on clues in the contractor’s name and business type: ($514 + $310) × 100% = $824 review estimate.
This percentage is an assumption, not verified tax status or a measured chance of an error. The estimate helps decide what to review first; it is not a tax bill. Confirm the details with your tax adviser before acting.
Tax-rule references used in this calculation
Potential tax withholding: IRC §3406. Potential tax form penalty: IRC §6721; Rev. Proc. 2024-40.
Why this estimate?
Higher estimates appear first so you can review the costliest potential mistakes first, not just the most warnings.
$22,400 paid × 24% in taxes that might need to be withheld from payments = $5,376.
We use 15% of these potential costs based on clues in the contractor’s name and business type: ($5,376 + $0) × 15% = $806 review estimate.
This percentage is an assumption, not verified tax status or a measured chance of an error. The estimate helps decide what to review first; it is not a tax bill. Confirm the details with your tax adviser before acting.
Tax-rule references used in this calculation
Potential tax withholding: IRC §3406.
Why this estimate?
Higher estimates appear first so you can review the costliest potential mistakes first, not just the most warnings.
$3,120 paid × 24% in taxes that might need to be withheld from payments = $749.
We use 100% of these potential costs based on clues in the contractor’s name and business type: ($749 + $0) × 100% = $749 review estimate.
This percentage is an assumption, not verified tax status or a measured chance of an error. The estimate helps decide what to review first; it is not a tax bill. Confirm the details with your tax adviser before acting.
Tax-rule references used in this calculation
Potential tax withholding: IRC §3406.
Why this estimate?
Higher estimates appear first so you can review the costliest potential mistakes first, not just the most warnings.
$9,400 paid × 24% in taxes that might need to be withheld from payments = $2,256.
We use 15% of these potential costs based on clues in the contractor’s name and business type: ($2,256 + $0) × 15% = $338 review estimate.
This percentage is an assumption, not verified tax status or a measured chance of an error. The estimate helps decide what to review first; it is not a tax bill. Confirm the details with your tax adviser before acting.
Tax-rule references used in this calculation
Potential tax withholding: IRC §3406.
Why this estimate?
Higher estimates appear first so you can review the costliest potential mistakes first, not just the most warnings.
Payments are below $2,000, so this model includes no tax withholding or penalty cost. A zero estimate does not clear warnings or prove that no tax reporting is required.
We use 100% of these potential costs based on clues in the contractor’s name and business type: ($0 + $0) × 100% = $0 review estimate.
This percentage is an assumption, not verified tax status or a measured chance of an error. The estimate helps decide what to review first; it is not a tax bill. Confirm the details with your tax adviser before acting.
Tax-rule references used in this calculation
Payment threshold: OBBBA §70435.
- 01Check your vendor payment spreadsheetUpload your spreadsheet as a .csv file. The first 10 vendors are checked free, with no sign-up required. No file ready? Explore the sample results above.
- 02See which mistakes could cost the mostWe rank vendors by estimated financial risk, using the amount paid this year and any missing or incorrectly formatted tax identification numbers. The highest estimated costs appear first so you know where to focus your review.
- 03Treat the estimate as a guide, not a tax billThe estimate is adjusted using clues in each vendor's name and business type. These are assumptions, not confirmed tax status. We check tax number format, not whether the number belongs to the vendor. Confirm the details with your tax adviser before acting.
- 04Review the highest-risk details firstStart with the vendors at the top of the list. For a critical finding, use the acknowledgment button after checking the vendor's details. It marks the finding as reviewed but does not correct the information or change the estimated risk.
Find tax number issues, not proof of identity.We flag missing or incorrectly formatted tax identification numbers. A correctly formatted number does not prove it belongs to the vendor. Confirm the vendor's details before relying on them.
Uploading does not automatically save your vendor details.Your spreadsheet is sent to our server and processed in memory. It is not saved to the app's database unless you choose to save the results.
Try the sample without uploading client data. The sample results above show what the check finds and which vendors to review first. You can explore them without a file or an account.
Review the costliest potential mistakes first. We rank vendors using payment totals, potential taxes and penalties, and assumptions about their business type. Estimates are a review guide, not money you owe. Confirm the details and current tax rules with your tax adviser before acting.
Generated emails still need human review. Paid plans can draft requests for vendor tax details. Have a tax professional check each draft before sending; the tool does not send emails or file tax forms for you.
Before you check your vendor list.
Check your first 10 vendors free. No paid plan needed.
Use the upload button above, or explore the sample results without a file, to see which potential tax mistakes could cost the most. No sign-up needed. Estimates are a review guide, not a tax bill. The $29/month plan adds more vendors, downloads, saved results, and draft emails requesting vendor tax details.