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How to write a terms of reference (ToR)

How to write a terms of reference (ToR): the most important document in hiring a consultant, and the most neglected. What to include and avoid.

22 June 20267 min read

Of all the documents involved in hiring a consultant, the terms of reference does the most work and gets the least attention. It is the brief that defines an assignment: what needs doing, why, by when, and to what standard. Get it right and good experts compete to deliver exactly what you need. Get it wrong and you spend the budget discovering that you and the consultant pictured two different jobs.

We cover the broader question of scoping an assignment separately. Here the focus is narrower and more practical: the terms of reference itself, often shortened to ToR.

What a terms of reference is

A terms of reference is the written specification for a piece of consulting work. It sets out the background, the objectives, the scope, the deliverables, the timeline, and the profile of the person or team you are looking for. In the development and climate sectors it is close to universal: funders, NGOs, and government agencies almost always issue one before they engage a consultant, and proposals are written and judged against it.

Why it carries so much weight

The ToR is the backbone of everything that follows. Consultants write their proposals from it, so a vague brief produces vague, padded proposals that are hard to compare. It becomes the basis of the contract, so anything left out is hard to ask for later without renegotiating. And it is the yardstick for judging whether the work succeeded. A precise ToR is the cheapest quality control you will ever buy, because it does its job before any money is spent.

What should a terms of reference include?

Most strong terms of reference cover the same building blocks:

  • Background and context: the situation, the problem, and why the work is needed now, enough for an outsider to understand the assignment.
  • Objectives: what the assignment is meant to achieve, stated as outcomes rather than tasks.
  • Scope of work: the activities expected, and just as importantly, what is out of scope.
  • Deliverables: the concrete outputs, whether a report, a dataset, a workshop, or a strategy, with the form and quality expected.
  • Timeline: milestones and the final deadline, with a realistic number of working days behind them.
  • Qualifications: the experience, skills, and sector knowledge the consultant needs.
  • Management and reporting: who the consultant answers to, how often, and how the work will be reviewed.

A budget or fee envelope often sits alongside, whether stated openly or held back for negotiation.

Objectives, activities, and deliverables are not the same

The single most useful distinction to get right is between these three. An objective is the change you want, such as better-informed investment decisions. An activity is the work done to get there, such as interviews, analysis, or a workshop. A deliverable is the tangible thing handed over, such as a written options paper. Weak briefs blur them, listing activities as if they were results. Strong ones keep the chain clear: this deliverable, produced through these activities, serves this objective.

The most common mistakes

A few failures recur often enough to name:

  • Too vague. Objectives so broad that any work could satisfy them, which guarantees a mismatch.
  • Too prescriptive. Specifying the method in such detail that you foreclose the expertise you are paying for. Say what you need, and let the specialist propose how.
  • Scope and budget that do not match. Ten days of fee for a hundred days of work is the fastest route to a disappointing result.
  • No clear deliverables. If you cannot say what will be handed over, neither can the consultant.
  • An unrealistic timeline. Good people decline impossible deadlines; the ones who accept them often should not have.

How much detail is enough

The art of a ToR is saying enough to align without saying so much that you crowd out judgement. A useful test: include everything a qualified expert needs to scope the work accurately and price it fairly, and stop there. Define the what and the why in full, and leave room for the consultant to own the how. That balance attracts better proposals and better people, because it signals a client who knows the difference between direction and micromanagement. For evaluations in particular, anchoring the brief to the OECD-DAC evaluation criteria gives both sides a shared, recognised frame to work from.

Direction, not micromanagement. That is the whole craft of a ToR.

Frequently asked questions

What is the difference between a terms of reference and a contract?

The ToR defines the work: objectives, scope, deliverables, and timeline. The contract is the legal agreement that engages the consultant to deliver it, and it usually incorporates the ToR by reference. The ToR comes first and shapes the contract.

What is the difference between a terms of reference and a scope of work?

They overlap but are not the same. A scope of work is usually one section of the wider terms of reference, listing the activities to be done and what is in and out of scope. The terms of reference is the fuller brief around it: background, objectives, deliverables, timeline, qualifications, and reporting. The scope of work says what gets done; the ToR says why, by when, and to what standard.

How long should a terms of reference be?

Long enough to brief a qualified stranger and no longer. Many sit between two and six pages. Padding does not add clarity, but missing a deliverable or a timeline does real damage.

Should a ToR include the budget?

It depends on the client's procurement style. Stating a fee envelope helps consultants pitch realistically and avoids wasted proposals, while withholding it invites a wider range of bids. Either can work, but a hidden budget paired with a huge scope frustrates everyone.

Who should write the terms of reference?

The commissioning team that understands the problem, often with input from a technical specialist. The person closest to the need writes the sharpest brief; a generic template filled in carelessly produces a generic result.

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