Form 940 filing: 4 checks to make before you submit it

Key takeaways

• Identify which form sections apply.
• Explain differences between payroll and your labor burden model.
• Use Schedule A for an applicable credit reduction.
• Review the relevant instructions and retain the filing record.

Estimators and owners often treat Form 940 as a year-end chore for the bookkeeper. That is a mistake if you build labor burden into bids. If your estimates use payroll records, compare their wage inputs with the applicable return entries. Differences need reconciliation and may reflect timing, employee population, or wage bases. You usually find out only after the work has been priced and sold.

This post walks through four checks to make before you submit the return. None of them is hard. Use organized payroll records to investigate mismatches that matter for labor burden. The checks rely on the official instructions for Form 940, so read the instructions for the tax year you are filing.

Before you start: gather the right documents

Many mismatches come from working with the wrong copy of a document, so set up your file first. You will need five things:

• The payroll register for the full year, exported from your payroll system rather than rebuilt from memory or from a monthly summary.
• The quarterly payroll tax reports for the same year, so you can see how the payroll totals were reported during the year.
• The Form 940 instructions for the year you are filing, saved as a PDF so you can cite the exact line.
• Last year's Form 940 as a baseline. You are looking for changes, and the prior return shows what a normal year looked like.
• The labor burden model you used for bids in that year, with its assumptions written down. If the model is a spreadsheet, note which cells hold wage inputs and which hold rates.

With those five items in one folder, the checks go quickly. Without them, you will spend most of your time searching for the right number instead of comparing it.

Check 1: confirm which parts of the form apply to you

Start with the structure of the form before you enter a single number. The instructions include a rule that is easy to skip past. The IRS states that "If line 9 applies to you, lines 10 and 11 don't apply to you." ( Instructions for Form 940) In other words, the form has branches. If you fill in every line from top to bottom, you can report amounts that do not belong to your situation, and a reviewer may not notice until the numbers are already in the system.

Read the instructions for line 9 and decide which branch you are on. Write the answer on the worksheet or in a file note, with the reason. A reviewer who sees a blank line 10 or line 11 should be able to tell right away that it was left blank on purpose, not forgotten. That note also saves time the next year, when someone has to decide the question again.

The same instructions add a section for a specific type of filer. The IRS explains that "Aggregate return filers must use the new Aggregate Return Filers Only section on Form 940 to identify whether they're filing an aggregate return as a section 3504 agent, certified professional employer organization (CPEO), or other third party." ( Instructions for Form 940)

For many contractors and owner-operated firms that run their own payroll, this section may not apply. But if you use a professional employer organization, a payroll service that files under its own arrangement, or another third party for payroll, find out who files the return. Then confirm that the aggregate section matches that arrangement. Do not assume the vendor's default setup fits your company. Investigate any mismatch in the filing arrangement before comparing payroll figures.

The estimating impact is straightforward. If your burden model assumes your company's own payroll, but the return reflects a third party's aggregate filing, establish comparable company-level figures first. Investigate the filing structure before treating a gap as a payroll error.

Check 2: tie the wage figures to payroll and to your labor burden

This is the core check. Pull the payroll register for the full year and total the wages paid to employees. Then compare those totals with the wage entries on the Form 940 worksheet and with the wage inputs in your labor burden model for the same year. Use the register as the source of truth. If the register and the return disagree, that is a finding to investigate. If the register and the model disagree, that is a finding to explain.

Three things commonly cause differences, and you should check each one.

The first is timing. Late payroll runs or a pay date crossing year-end can shift the comparison between years. Write down the cutoff you used in the model and the cutoff you used for the return. Then the comparison is apples to apples, and you can see whether the gap is timing or something else.

The second is who is included. Owners, officers, family members on payroll, and workers who left mid-year are easy to miss in a burden model that was built from a rate sheet or a worksheet. Check that the employee population in the payroll register matches the population in your model. Check how owner or officer pay is treated in each place, because it may be counted in one and left out of the other.

The third is wage categories. Check the instructions for the wage figure each entry requires. Those are different figures, and mixing them up is one of the most common ways a burden model and a return drift apart. Compare each line on the return to the matching number in your model. If your model uses one wage figure for every purpose, write that assumption down and explain the difference in the file.

Contractors need a separate look. Identify subcontract costs in your records and reconcile them separately from employee wages. Make sure your labor burden model does not count subcontract payments as employee wages, and make sure the return reflects only the wages the instructions call for. Subcontract cost still belongs in your bid, but in its own line, not inside the payroll burden.

When the totals differ, do not adjust the return to match the model, and do not adjust the model to match the return until you know why. Find the reason first. A difference caused by timing is a note in the file. If an employee is missing, correct the record containing the omission; a payroll omission may also affect other filings.

For related estimating inputs, review employer tax figures for labor burden.

Illustrative example: trace a wage difference

Using illustrative amounts, suppose payroll wages total 20 and the model includes 10. The difference is 10. Compare the employee lists and cutoffs before changing either figure. If an employee's wages were omitted only from the model, correct the model and document the reason. This comparison explains a difference; it does not calculate tax.

Check 3: look at the credit reduction and Schedule A

The third check covers the credit reduction, which is easy to overlook because it sits outside the basic wage math. The IRS instructions direct you to a specific schedule for this purpose: "Use Schedule A (Form 940) to figure the credit reduction." ( Instructions for Form 940) If your return includes a credit reduction, you need to complete that schedule and carry the result correctly to the form. If it does not apply to you, confirm that and do not leave a carried-over credit reduction in the file from an old worksheet.

For estimators, the practical point is simple. Reconcile any applicable credit reduction with your labor burden model. If the labor burden in your bids is built from a rate or a prior-year total, check whether it reflects the applicable adjustment. Compare the amount on the return with the amount in your model. If they differ, the reason should be written in your notes. Do not assume the difference is rounding. Rounding produces small, predictable gaps, and a credit reduction produces a gap you can trace to a specific schedule.

Keep Schedule A with the copy of the return. A reviewer who wants to trace the reduction later should be able to follow it from the schedule to the form to the labor burden model without rebuilding the calculation. If you cannot trace it, the reduction is not documented well enough, and that is a problem regardless of whether the number is correct.

For the broader estimating comparison, see construction unemployment tax figures for bid estimates.

Check 4: confirm applicable entries, then check the filing record

The final check is about the details that connect the return to the money and to the record the IRS keeps. The instructions point you to other sections for more detail. The IRS states, "For more information, see the instructions for line 14, later." ( Instructions for Form 940) They also state, "For more information, see the instructions for line 15b and Direct Deposit, later." ( Instructions for Form 940)

Read both sections before you submit. Reconcile each applicable entry to its instructions, calculation, and supporting records. A payment entry that does not match the return can lead to later correspondence, and it is easier to catch before submission.

Once the return is filed, confirm it on the record side too. The IRS states, "You can now access your Form 940 return transcript for tax years 2023 and later using your IRS business tax account." ( Instructions for Form 940) Pull the transcript, compare available entries with corresponding return entries, and file it with the labor burden worksheet. If the transcript and your copy disagree, you have an early warning before the next bid cycle, and you can deal with it while the details are still fresh.

Put the checks into your estimating routine

Turn the four checks into a short list that someone can initial. A checklist works best when each item asks for a specific answer, not a general yes or no. Use this list as a starting point:

• Confirm the branch on line 9, and write down which branch applies and why.
• Confirm whether the aggregate return section applies, and name the party that files the return.
• Reconcile total wages and taxable wages to the full-year payroll register.
• Match the employee population and the payroll cutoff to the labor burden model.
• Complete Schedule A if a credit reduction applies, or record that it does not.
• Read the instructions for line 14 and line 15b, and reconcile the applicable entries.
• After filing, pull the transcript and compare it to your copy of the return.
• Record any difference, its cause, and the person who approved the fix.

Keep the list short enough that people will actually use it. Keep each item specific enough to review consistently.

Know who reviews what

Separate the work so that one person does not check their own numbers. In many small firms, the bookkeeper prepares the return, the estimator maintains the labor burden model, and the owner signs off on the filing. Those roles should be clear. The estimator should not change the return, and the bookkeeper should not change the bid assumptions without talking to the estimator first.

A simple way to split the work is to have the bookkeeper own the register and the return, the estimator own the burden model and the reconciliation memo, and the owner own the final decision on any difference that cannot be explained. The reconciliation memo does not need to be long. A page that lists each check, the figures compared, the result, and the reason for any difference is enough for most firms.

Owners who sign the return should also understand the basic logic behind it. You do not need to read every line of the instructions, but you should know which figures drive labor burden and where those figures appear on the return. Ask for the reconciliation before you sign, not after a bid goes out with a number that no one can defend.

Read the common mismatches the right way

Certain patterns show up again and again. Recognizing them saves time, because each pattern points toward a likely cause.

If the return shows more wages than the labor burden model, a likely cause is that the model left out some employees, such as owners, a mid-year hire, or a seasonal crew. Check the employee list first. A second possibility is that the model uses a rate applied to a smaller base than the actual payroll.

If the return shows fewer wages than the model, the model may include accrued pay that was not yet paid, or it may include subcontract payments that belong in a separate cost line. Check the cutoff date and the cost categories in the model.

If the total wages and the taxable wages are different, that is expected. The question to answer is whether your model uses the right figure for each purpose. A model that uses total wages where the taxable amount is needed will overstate the cost, and a model that uses taxable wages where total wages are needed will understate the labor cost of the crew.

If there is no difference between the return and the model, but the burden still seems wrong, the problem is probably in the assumptions rather than the numbers. A burden percentage can be built on a rate that is out of date, a prior-year total that no longer reflects the current crew, or a benefit cost that was never updated. Check the assumptions, not just the arithmetic.

When a check fails

A failed check is useful. It means the review found something before the filing or the bid went out. The worst response is to force the numbers to agree. A plug figure may make the two documents match, but it hides the real problem and makes the next reconciliation harder.

Instead, stop and document the difference. Write down the two figures, the source of each, and the question you are trying to answer. Then find the cause. In most cases the cause is one of the patterns above, or it is a simple entry error that can be corrected at the source. If the cause is a payroll error, correct the payroll records first, and then update the return and the model from the corrected records.

If you cannot find the cause in a reasonable time, bring in the person who prepares the return or a tax professional. Ask how to resolve the difference while meeting applicable filing requirements.

Keep the file, not just the form

The filed return is one document. The reconciliation memo, the marked-up instructions, the payroll register extract, the transcript, and the labor burden worksheet are the record that explains how the numbers were built. Keep them together, and name the folder by tax year so the next person can find it. When someone asks in six months why the burden moved, the file should answer the question without a search.

The file also makes next year easier. A reviewer can start from last year's memo, see which assumptions were confirmed, and focus on what changed. That is how a routine check becomes a reliable part of estimating instead of a scramble before a deadline.

Before you submit

Today, gather the documents in one folder and record the first unexplained difference for review.

Questions before you submit

Should the model and return always match?

No, differences can reflect timing, employee population, or wage bases. Explain each difference before changing a figure.

Where can you get the filed record?

Use your IRS business tax account to access a Form 940 return transcript for tax years 2023 and later. Compare corresponding available entries and keep the transcript with your return.