Back-to-Back Contracts Explained: What Flows Down to the Subcontractor

A back-to-back contract is a subcontract that passes the main contract's terms down to the subcontractor, so its rights and obligations mirror the main contractor's own. Working "on a back-to-back basis" means accepting the same standards, deadlines and risks that sit above you in the chain. The danger is signing a contract you have never read.

What Does Back-to-Back Basis Mean?

'On a back-to-back basis' means the subcontract is drafted to match the main contract. Whatever the employer can demand of the main contractor, the main contractor can demand of you for your package. Under the FIDIC Red Book, the main contractor is responsible for the acts or defaults of any subcontractor as if they were its own (Sub-Clause 4.4 of the 1999 edition). Back-to-back drafting is how it avoids being liable upward for something it cannot recover downward.

Incorporation happens in one of two ways:

• The careful way lists the main contract clauses that apply and states how each is adapted.
• The common way is one sweeping sentence: the subcontractor is deemed to know the main contract, and its provisions apply as if repeated, with the necessary changes.

That sweeping phrase is often written in Latin, and what mutatis mutandis means in a contract matters here, because nobody has agreed which changes are necessary. Every gap becomes an argument later, usually over money.

Back-to-Back Agreement vs Subcontract: Is There a Difference?

A back-to-back agreement is a contract written to mirror another contract, so the party in the middle passes the same terms, and the same risk, straight through to the next party in the chain. In construction it is not a separate category of contract - it is a drafting choice, a way of writing the subcontract so its terms track the main contract above it. Traders and banks use the phrase the same way, for matching sale or credit arrangements that protect the party in the middle.

The real distinction is between a bespoke subcontract and a back-to-back one. A bespoke subcontract writes out its own terms in full, sized to the package. A back-to-back subcontract borrows its terms from a document negotiated by two other parties, often before you were invited to tender.

Either way, you still have no contract with the employer: obligations flow down, but rights against the employer do not automatically flow up. Outside a specific statutory right, you can be held to the employer's standards with no direct route to the employer's money.

In the UAE, the Civil Code bars a subcontractor from claiming against the employer for sums the main contractor owes it, unless that debt has been assigned. Qatar's Civil Code is different: it gives subcontractors a limited direct claim against the employer, capped at what the employer still owes the main contractor when the claim is brought.

What Flows Down in a Back-to-Back Subcontract

Five areas carry most of the risk in a back-to-back subcontract:

• Time bars - a tighter notice window than the main contractor gets upstream.
• Liquidated damages - a daily rate sized to the whole project, not your package.
• Payment - tied to whether the main contractor is paid by the employer.
• Dispute resolution - bound into a forum you may not be a party to.
• Design responsibility - a fitness-for-purpose promise that can outrun your insurance cover.

FIDIC gives the main contractor 28 days from actual or constructive awareness of an event to notify a claim, under Sub-Clause 20.1 of the 1999 forms and 20.2 of the 2017 forms. If your subcontract repeats the same 28 days, the main contractor may be unable to pass your claim upward in time. FIDIC's own Conditions of Subcontract for Construction shortens the subcontractor's notice period for exactly that reason, so you face a tighter time bar than the main contractor does.

The main contract liquidated damages rate is sized to the employer's loss on the whole project. Take a QAR 6 million cladding package under a main contract carrying delay damages of QAR 120,000 a day: fifty days of delay at the unadjusted rate would consume the entire subcontract value.

This is what most people mean by back-to-back payment terms: your payment is tied to the main contractor being paid by the employer. A pay-when-paid clause delays your money. A pay-if-paid clause can cancel it, as our guide to pay-when-paid and pay-if-paid clauses explains.

A main contract may send disputes to a dispute board and then arbitration, and a back-to-back subcontract may bind you to a process you are not party to.

Design-build forms such as the FIDIC Yellow and Silver Books require the works to be fit for the purposes defined in the contract. Flow that down to a subcontractor who designs part of the works and you have promised a result - cover most professional indemnity policies do not give, since they are usually written around reasonable skill and care, not results.

Where Back-to-Back Breaks Down

On paper a back-to-back subcontract looks balanced. In practice it breaks in three places, and the subcontractor usually absorbs the break:

• Mismatched notice periods: many subcontracts start your clock from the event itself, or from when the main contractor became aware of it, so part of your window can be gone before an engineer's instruction reaches you second-hand.
• Information you never see: most subcontractors receive the subcontract and a schedule of extracts, not the particular conditions, amendments, the engineer's correspondence or the claims running upstream - a mirror only reflects what is placed in front of it.
• The dispute clause: English courts have long been reluctant to let general words of incorporation carry an arbitration clause across from a contract made between different parties.

In Habas Sinai v Sometal, decided in 2010, the Commercial Court gave subcontracts incorporating a main contract as a common example of this two-contract situation. The judge observed a particular need to be clear that the parties intended to incorporate the arbitration clause, leaving you unsure which forum hears your claim at the moment you need one.

Are Back-to-Back Payment Terms Enforceable?

It depends on where the work is done and which law governs the subcontract - the answer ranges from ineffective to fully effective. For construction work in England, Wales or Scotland, section 113 of the Housing Grants, Construction and Regeneration Act 1996 deals with it directly, whatever law the contract chooses. Choosing English law for a project in Qatar or the UAE does not bring the Act with it.

Where the Act applies, a provision making payment conditional on the payer being paid by a third person is ineffective, unless that third person, or someone further up the chain, is insolvent. Amendments in force since 2011 also catch pay-when-certified wording, where payment depends on a decision under another contract.

Two cautions apply even there. The insolvency exception means a conditional payment clause can still bite when the employer becomes insolvent - exactly when you need the money most.

The Act also excludes the assembly, installation or demolition of plant and machinery, and the steelwork that supports it, on sites whose primary activity is power generation, nuclear processing or water and effluent treatment, or the production, processing or bulk storage of oil, gas, chemicals, pharmaceuticals, steel or food and drink. A process plant subcontractor may have none of these protections.

Qatar and the UAE have no equivalent statute. A clearly drafted pay-when-paid clause is therefore generally upheld as a timing mechanism, and the argument is about how far it reaches. Whether pay-if-paid wording can cancel the debt altogether is far less settled. Qatar's Court of Cassation has held that a pay-when-paid clause permits only a temporary and reasonable postponement of payment, not an indefinite one - that helps on timing, but it does not turn the clause into a payment guarantee.

What to Negotiate Before You Sign a Back-to-Back Subcontract

We review hundreds of subcontracts across the GCC every year, and the pattern is consistent: the subcontractor negotiates the price hard and the incorporation clause not at all. The problem is rarely flow-down itself. It is flow-down that nobody has read against the package, the programme and the insurance.

Before you sign, negotiate on five fronts:

1. Ask for the main contract, prices redacted if necessary.
2. Ask for a schedule of which clauses apply and how each is adapted, plus a precedence clause so your specific terms beat the general incorporation.
3. Size the liquidated damages and the liability cap to your subcontract value.
4. Put a longstop date on payment.
5. Require upstream instructions and notices to reach you within a fixed number of days, and start your notice clock from receipt.

Negotiate specific carve-outs rather than rejecting flow-down wholesale, because few main contractors will accept the second. Our guide on how to review a construction subcontract before you sign covers the rest of the document. The terms to fix first are the red flags in a subcontract handed down by the main contractor.

At CALIM, we read the flow-down clause against the main contract before signature, then run the notices, payments and claims under it once work starts. That is the core of our commercial management for SME contractors. The cheapest moment to fix a back-to-back problem is before it binds you.

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