Most carbon offtake agreements run between 5 and 15 years. Early-stage removal projects, particularly direct air capture and large-scale afforestation, sometimes ask for longer terms to underwrite the project's capital expenditure.

A forward contract typically covers a short to medium term (1-5 years) with a fixed volume and price. A carbon offtake agreement is longer (5-15 years), covers larger total volumes, and usually includes more detailed provisions on quality, underdelivery, and replacement.

Reversal risk is shared. The registry buffer pool absorbs the first layer of losses across all projects in the registry's portfolio. Beyond the buffer pool, the contract allocates residual reversal risk through specific clauses, typically requiring the seller to replace lost credits from their wider portfolio. Buyers who skip the contractual layer carry the residual risk themselves.

A make good clause sets out the steps a seller must take when they cannot deliver the contracted volume of credits. Instead of triggering an immediate default, it gives the seller defined cure options: replacement credits from another project, an extended delivery period, or liquidated damages. The clause is what stops a single bad year on a project from collapsing the whole contract.

Three pricing models dominate: fixed price for the full term, fixed escalating with an annual uplift, and floating or indexed pricing that tracks a market benchmark. Hybrid structures combining a fixed floor with index participation are increasingly common. Payment is usually on delivery, with milestone payments used in pre-issuance offtakes and upfront payments reserved for cases where the buyer is effectively co-financing the project.

Because the two markets are used for different project types. Spot transactions are dominated by lower-cost avoidance credits and legacy supply across all quality levels. Offtakes are dominated by durable removals (DAC, BECCS, biochar, ERW) which command high prices regardless of how they are sold. The offtake mechanism itself does not add cost. It is the mechanism through which expensive, scarce, high-permanence credits are typically procured, because long-term contracts are what makes those projects financeable in the first place.