Prime or sub on public work: the trade you are really making

One of you signs the contract and carries the risk. The other gets paid when the first one does. Both can be right — for different jobs.

October 24, 2026 · 3 min read · by Chasedirt

On the same job, being the prime and being a subcontractor are two different businesses. The prime holds the contract with the public owner, carries the bond, and takes the profit and the risk that come with both. The sub does the work described in its scope and gets paid on the prime's cycle. Deciding which one you are is a decision about cash flow and risk appetite as much as about capability.

Bonding is the first constraint

Public work usually wants a bid bond with the bid and performance and payment bonds on award. Those come out of your bonding capacity, which is a function of your financial statements, your history and your bank. As a sub you generally do not post a bond to the owner, so a job larger than your capacity is still a job you can do — as somebody else's sub. That is not a lesser business, it is a different one, and plenty of strong contractors stay there deliberately.

Who carries the payment risk

As prime, you are on the owner's payment cycle: retainage may be held until completion, and payment applications move at the speed of the owner's process. As a sub, you are on the prime's cycle, which contractually flows down from the owner's — but in practice depends on the prime paying on time, and on how much leverage you have if they do not.

Read the contract for the payment terms before you agree to them, including how retainage is handled and what happens if the owner is late paying the prime. Verbal assurances are not terms. If a prime says "we always pay in thirty days", the contract is the thing that will be read at the moment it matters.

The scope gap

Every project has one piece that nobody priced. As prime, that piece is yours by default when the contract is signed — the gap comes out of your margin. As a sub, a gap at the edge of your scope is a change order negotiation, which is a much better place to be. This is why primes lose money on jobs they were certain they had priced, and subs often do not.

The paperwork is different

As prime expect to provide the bid, the bonds, insurance certificates naming the owner as additional insured, safety documentation, a subcontractor list, and the schedule. As a sub expect to provide insurance, a W-9, your licence, and sometimes a scope letter. None of it is difficult; all of it is required quickly.

The thing to watch as a sub

If a prime asks you to price a scope for a bid they are preparing, understand that you may be helping them learn the market rather than being chosen. Being named in the bid as the intended subcontractor is a much stronger position than "we will use you if we win". If you are going to give a number, give it with a validity period and ask whether you will be named. Some primes will; some will shop it, and finding out which is which is part of the job.

How to choose

• Prime when the job is within your bonding capacity, you know the owner or the site, and you can carry the cash flow through the payment cycle.
• Sub when the job is bigger than your capacity, the scope is a clean fit for what you do best, or the cash flow of a prime's retainage would hurt more than the margin would help.
• Either when the job is small enough that the paperwork costs more than the risk.

One more consideration that does not appear in any bid document: as prime you own the relationship with the buyer, and that relationship is what brings the next job. As a sub you own the relationship with the prime, which can be worth just as much — a good prime with steady public work is a pipeline that never gets advertised.