Compliance with Confidence: When to Use Shall vs Should vs Will for High-Stakes Proposals

Step 1 — Define the semantic and pragmatic differences

In high-stakes proposals, the verbs shall, should, and will carry distinct semantic and pragmatic weight. Understanding those differences is the foundation of writing clear, persuasive, and defensible compliance language.

• Shall: Historically and conventionally, shall signals obligation, mandate, or requirement. In legal and contractual contexts, shall is used to impose duties on a party. Its normative force is strong: when a clause says “The Contractor shall submit monthly reports,” it creates an expectation that failure to submit is a breach. Because of this force, many plain-language initiatives advise limited use of shall unless the writer intends to create legal effect. In proposals that will become part of a contract or that will be incorporated into a contractual statement of work, shall remains appropriate where you want to impose immutable obligations on the proposer, a supplier, or the counterparty.

• Should: Should expresses recommendation, guidance, or preferred practice. It signals a softer normative stance: compliance is advised but not compulsory. For example, “The system should encrypt data at rest” suggests a desirable practice that could be overridden or documented with justification. Should is useful when the drafting party wants to encourage a course of action while preserving flexibility—important for proposals where technical feasibility or negotiation may affect final requirements.

• Will: Will functions primarily to express intent or future action. In proposal language, it is typically used to commit the proposer to deliverables, schedules, or behaviors: “The Contractor will deliver the first prototype in 90 days.” Will does not inherently impose an obligation on the other party; it states what a particular actor intends or promises to do. Pragmatically, will can be strong as a promise from the proposer, but it differs from shall because it is phrased as an expression of intent rather than a prescriptive rule.

Understanding these semantic roles matters because readers—reviewers, contracting officers, and executives—interpret these words through established expectations. Misusing them can change legal meaning or weaken a proposal’s clarity and persuasiveness. Use shall when you need enforceable requirements, should when you mean recommendations or best practices, and will when you are stating your own commitments or future actions.

Step 2 — Map to audience expectations and tone (US Federal Plain Writing & UK MOD)

Plain-language guidance from US Federal Plain Writing and the tone expectations of the UK Ministry of Defence both emphasize clarity, active voice, concise structure, and a professional executive register. These principles intersect with the normative differences among shall, should, and will to create practical rules for high-stakes proposal writing.

US Federal Plain Writing emphasizes that documents should be understandable on first reading, use active voice, and avoid unnecessary legalese. In that environment, the use of shall should be deliberate: reserve it for clauses that must carry legal or contractual weight. Where a sentence only intends to recommend or explain, replace shall with plain verbs that reflect the actual intention (should, will, must when appropriate, or even simpler constructions). Short sentences and concrete verbs reduce ambiguity. For instance, active constructions — “The Contractor shall deliver” versus passive or convoluted alternatives — make agency and obligation unmistakable.

The UK MOD tone expects executive-level credibility: language should be confident, precise, and authoritative without being needlessly archaic or bureaucratic. The MOD prefers plain English and directness; archaic or ambiguous phrasing undermines credibility. That means avoiding phrases like “it is hereby required” when a simple shall-based or will-based construction suffices. The broader point for both US and UK contexts is to balance legal force with readability: preserve the force of requirements where needed, but express them in active, concise language to maintain executive clarity.

When converting older or overly formal text, the goal is not only to swap words but to realign the sentence to audience expectations. If shall is legally necessary, keep it but rework the surrounding syntax: remove nested clauses, break long sentences into shorter ones, and ensure the actor is front and center. If the intent is a recommendation, substitute should and reduce layers of modal hedging that dilute the message. If you are promising delivery as the proposer, use will to convey commitment and pair it with specific, measurable terms (dates, deliverables, acceptance criteria) to meet executive scrutiny.

Strategic tone choices also affect perceived responsibility. Using will in a proactive, active-voice sentence emphasizes the proposer’s accountability. Using should with a clear rationale positions the recommendation as reasoned and professional. Using shall in a simple, direct clause signals that the writer has allocated risk and is defining obligations explicitly.

Step 3 — Readability targets and quantitative checks

Concrete readability targets help reconcile legal precision with plain-language goals. For high-stakes proposals addressed to executives and contracting officials, aim for measurable targets that make the text testable and revisable.

Recommended targets:

• Average sentence length: 15–20 words. Shorter sentences reduce cognitive load and make obligations easier to parse.
• Flesch-Kincaid Grade: approximately 8–10, depending on the audience’s technical sophistication. Lower is better for general accessibility; higher may be acceptable for specialized technical annexes.
• Passive voice: under 10–15% of sentences. Excessive passive voice obscures actors and responsibility.

How to test and iterate: start by scanning the draft for compliance verbs (shall, should, will, must). Flag each sentence containing one of these verbs and run a simple diagnostic: count words, identify dependent clauses, and note whether the actor is explicit and placed early in the sentence. For flagged sentences with excessive length or nested clauses, split them into simpler, active-voice constructions. Replace hedging where unnecessary.

A short algorithm for revision:

1. Locate compliance verbs. Search the document for shall, should, will, and must.
2. Ask: "Is this a legal/contractual requirement?" If yes, keep shall (or must, where legally required), but simplify the sentence structure and make the actor explicit.
3. If it is a recommendation or best practice, use should or other advisory verbs (recommend, advise, encourage) and mark the sentence as non-contractual.
4. If the sentence expresses the proposer’s commitment, use will and follow with measurable specifics (deliverable, date, acceptance criteria).
5. Apply readability edits: shorten to 15–20 words on average, convert passive to active where possible, and break multipart obligations into bullet points or numbered subclauses.
6. Recompute readability metrics and adjust until targets are met.

This algorithm forces a pragmatic decision for each compliance expression and pairs that decision with concrete edits that preserve or clarify normative force.

Step 4 — Style-checklist and application walk-through

A compact checklist turns the above principles into an operational routine that writers can run quickly on each compliance sentence. Apply this checklist in order for every sentence that signals compliance, obligation, or commitment:

1. Identify the actor (Who?). Ensure the actor is explicit and placed at the start of the sentence.
2. Identify the intent (Requirement, Recommendation, Commitment?). Decide: shall, should, or will.
3. Choose the verb accordingly: shall for requirements, should for recommendations, will for propositional commitments. Replace ambiguous modals (e.g., may, might) where they obscure intent.
4. Use active voice. Convert passive constructions by making the actor the subject.
5. Shorten: target 15–20 words. Break long sentences into two or more sentences or bullet points.
6. Make results measurable when possible: add deliverables, dates, acceptance criteria, or performance measures.
7. Preserve legal force: If a clause must have contractual effect, retain shall/must and ensure the rest of the sentence cannot be read as permissive.
8. Document the decision: add a tracked-change comment or a compliance-verb glossary entry explaining why you used shall/should/will.

After applying the checklist, run quantitative checks: recalc sentence length, recompute passive voice ratio, and update the Flesch-Kincaid score. The final practical step is document-wide consistency: maintain a compliance-verb glossary that defines how your proposal uses shall, should, and will, and apply that glossary across sections. For reviewers, use tracked edits and a short cover note explaining any conversions (for example, where you replaced several instances of shall with shall retained only for contractual clauses).

Consistency is crucial. Mixed or inconsistent use of shall, should, and will across a proposal creates legal ambiguity and undermines reader trust. By following the checklist, pairing each decision with revision and documentation, you preserve both the legal/contractual force where necessary and the plain-language clarity demanded by US Federal and UK MOD standards.

In summary, treating shall, should, and will not as interchangeable but as intentional signals—combined with active voice, short sentences, measurable targets, and a compact checklist—gives writers a repeatable method to craft compliance language confidently. That balance protects legal effect while making proposal text readable, credible, and executive-ready.