Getting your size calculation wrong can cost you a federal contract. A competitor who loses a set-aside award to you will often file a protest with SBA's Office of Hearings and Appeals, and if SBA finds you were actually large, the contract gets pulled. This guide explains the mechanics: how size is calculated, how affiliation inflates your numbers, and what a protest looks like from the inside.
The two measuring sticks: receipts and employees
SBA uses one of two methods depending on the NAICS code attached to the solicitation.
Annual receipts applies to most service and construction companies. The threshold varies by industry. A janitorial services firm (NAICS 561720) has a $22 million ceiling; a management consulting firm (541611) has $24.5 million. You find the threshold in the SBA's Table of Small Business Size Standards, which SBA updates periodically — the most recent revision took effect March 17, 2023.
Receipts are calculated as a three-year average. Take your total revenue for the three most recently completed fiscal years, add them together, divide by three. That number must sit below the threshold on the date you self-certify in SAM.gov.
Employee count applies mainly to manufacturing and some wholesale trade NAICS codes. Thresholds range from 100 to 1,500 employees depending on the industry. SBA counts employees as a 12-month average: add together the number of employees for each pay period in the preceding 12 months and divide by the number of pay periods. Part-time employees count the same as full-time.
One gotcha: if you've been in business fewer than three fiscal years, you average over however many years you have. If you've been operating for 18 months, you average over 18 months of receipts.
Affiliation: the part that surprises most companies
Affiliation is where small businesses routinely get tripped up. SBA's affiliation rules, codified at 13 CFR Part 121, require you to count the receipts or employees of any affiliated business as if they were your own.
Two companies are affiliated when one controls the other, or when a third party controls both. Control can be direct or indirect, formal or practical. SBA looks at ownership, officers, directors, key employees, and contractual relationships.
The most common affiliation scenarios:
Common ownership. If the same person owns 51% of your firm and 51% of another firm, those two companies are affiliated. Both sets of receipts count toward your size.
Common management. If the CEO of Company A also serves as the CEO of Company B, SBA may find affiliation even if ownership is different.
Economic dependence. If more than 70% of your revenue comes from a single other company over the previous three fiscal years, SBA can find affiliation with that company. This catches subcontractors who do almost all their work for one prime.
The ostensible subcontractor rule. This one is specific to subcontracting. If you're a small prime but you plan to subcontract the primary and vital requirements of the contract to a large company, SBA treats that large subcontractor as affiliated with you for purposes of the bid. The rule exists to prevent large companies from hiding behind small fronts.
Mentor-protégé agreements. SBA's mentor-protégé program has a specific exemption: a protégé in an approved SBA mentor-protégé agreement is not affiliated with its mentor solely because of that agreement. Outside the program, mentorship-style relationships with significant control elements can still trigger affiliation.
Unpacking whether you have affiliation issues requires looking at your cap table, your management structure, your major customer relationships, and any contracts or joint venture agreements. Many small businesses don't do this analysis until a protest forces the issue.
How a size protest works
Any offeror on a set-aside procurement can protest the apparent awardee's small business status. Protests must be filed with the contracting officer within five business days of notification that a competitor was selected. The contracting officer forwards the protest to SBA's Office of Government Contracting.
SBA then contacts the challenged company and asks for size information: tax returns, balance sheets, a list of affiliated entities, organizational documents, information about key officers. You typically have three to five business days to respond. The response package is your chance to explain your size calculation and rebut the affiliation allegations.
SBA issues a size determination within 15 business days of receiving a complete case file. If SBA finds you are small, the protest is denied and the contract proceeds. If SBA finds you are large, the contracting officer cannot make the award to you. In some cases, the contract goes to the next offeror in line.
You can appeal a size determination to SBA's Office of Hearings and Appeals (OHA). OHA decisions are final within SBA, though parties can then take the matter to the U.S. Court of Federal Claims.
What SBA actually reviews
SBA size examiners are looking for a few specific things:
Your tax returns. SBA matches the receipts you report in your size certification against IRS tax returns. Discrepancies raise flags. Make sure your SAM.gov certification and your actual financials are consistent before you submit any bid.
Ownership and control documents. Operating agreements, bylaws, shareholder agreements, stock certificates. If you have a minority investor with veto rights over certain decisions, that investor may have the ability to control your firm even without majority ownership.
Agreements with other companies. Subcontracting agreements, teaming agreements, joint venture agreements. SBA reads these closely for language that could indicate an ostensible subcontractor relationship or shared management.
Payroll records. For employee-based size standards, SBA wants payroll records or equivalent documentation going back 12 months.
Customer concentration. If one customer dominates your revenue, expect questions about economic dependence.
Three things to do before your next bid
Run your own affiliation analysis before you certify. Pull together a list of every entity where you, your co-owners, or your key officers have an ownership stake or management role. Add up the combined revenues or headcount. If the combined number pushes you over the size standard, you need to resolve those relationships before bidding or accept that you're large for that NAICS code.
Document your size calculation now, not after a protest. Keep a size calculation memo in your bid file: the three-year revenue figures, the source documents, and the affiliation analysis. If a protest comes in, you'll have five business days to respond. Having the analysis ready dramatically reduces the stress and the risk of missing something under deadline.
Check the NAICS code before you assume you qualify. Contracting officers sometimes assign NAICS codes that don't fit the work, or choose between two plausible codes with very different size thresholds. Under FAR 19.301-1, you can challenge the NAICS code designation before bids are due. Winning that challenge can mean the difference between qualifying as small and being shut out entirely.
Size determinations are not permanent. SBA re-evaluates your size as of the date of each self-certification. A company that qualified last year may not qualify this year if revenues grew or an affiliation issue surfaced. Build the analysis into your standard bid preparation process, not as a one-time exercise.
