Best Endeavours: Meaning, Examples, And Use In UK Contracts

If you run a small business, you’ve probably seen (or been asked to accept) a clause saying you must use “best endeavours” to do something.

It sounds sensible - who wouldn’t try their best? But in a contract, “best endeavours” can be surprisingly risky if you don’t pin down what it actually requires.

In this guide, we’ll break down what “best endeavours” means in UK contracts, why it matters for small businesses, and (crucially) give you plenty of examples of best endeavours in a sentence you can use in emails, proposals, and contract drafting.

What Does “Best Endeavours” Mean In UK Contracts?

In plain English, an endeavours clause is a promise about how hard you’ll try to achieve a particular outcome.

Instead of promising a fixed result (“we will obtain planning permission by 1 June”), an endeavours clause is usually used where the outcome depends on factors outside your control (for example, a landlord consenting, a regulator approving, or a supplier performing on time).

In UK contracting, the most common variations are:

• Best endeavours
• All reasonable endeavours
• Reasonable endeavours

There isn’t a single “one-size-fits-all” statutory definition, and courts don’t apply a rigid, universal ranking between these phrases in every case. The meaning often depends on:

• the wording of the contract as a whole
• the commercial context (what your business is actually trying to do)
• what steps are realistically available to you
• what is proportionate given cost, time, and impact on your business

This is why it’s worth getting the fundamentals of contract drafting right - including being clear about what’s a binding obligation and what’s not. (If you’re sanity-checking whether you’ve actually formed a contract, the basics in What Makes A Contract Legally Binding are a helpful starting point.)

Why Small Businesses Should Be Careful With “Best Endeavours”

For many small businesses, “best endeavours” can unintentionally become a promise that:

• forces you to spend more time and money than you expected
• requires you to prioritise that obligation over other work
• creates a dispute about whether you tried “hard enough”

That last point is the big one. Endeavours clauses often lead to arguments not about the end result, but about the steps you took (or didn’t take).

Best Endeavours In A Sentence: Practical Examples For Small Businesses

If you’re looking for best endeavours in a sentence examples to use (or adapt), the key is to keep them specific enough that the meaning is clear, but flexible enough that you’re not guaranteeing something you can’t control.

Below are practical examples you can use across common small business situations.

Best Endeavours In A Sentence (Everyday Business Communication)

• “We’ll use our best endeavours to deliver your order by Friday, subject to courier availability.”
• “The team will use its best endeavours to respond to all support requests within 24 hours.”
• “We’ll use our best endeavours to accommodate your preferred installation date, but we can’t guarantee availability.”
• “We’ll use our best endeavours to resolve the issue remotely before arranging an on-site visit.”

Tip: In customer-facing messages, it’s often safer to pair “best endeavours” with a clear qualifier (for example, “subject to availability” or “we can’t guarantee”). Otherwise, a frustrated customer may treat it as a hard promise.

Best Endeavours In A Sentence (Supplier And Delivery Scenarios)

• “The Supplier will use its best endeavours to procure substitute materials if the specified stock is discontinued.”
• “We will use our best endeavours to maintain continuity of supply during peak trading periods.”
• “The parties will use their best endeavours to agree an alternative delivery schedule if the original timeline becomes impracticable.”

Best Endeavours In A Sentence (Sales, Marketing, And Partnerships)

• “Each party will use its best endeavours to promote the launch on its social media channels for 30 days.”
• “The Agency will use its best endeavours to generate qualified leads, but does not guarantee sales.”
• “The parties will use their best endeavours to resolve any disputes in good faith before commencing formal proceedings.”

Best Endeavours In A Sentence (Regulatory Or Third-Party Approvals)

• “The Company will use its best endeavours to obtain the Landlord’s consent for signage, but consent is outside the Company’s control.”
• “The parties will use their best endeavours to secure the necessary approvals to complete the project.”
• “We will use our best endeavours to implement processes intended to support compliance with applicable laws and industry standards throughout the term.”

These are common, but they can also be high-risk if the “steps” are not defined - especially where third parties can delay, refuse consent, or impose costs.

How Hard Is “Best Endeavours” Compared To Reasonable Endeavours?

One of the biggest practical questions for business owners is:

Is “best endeavours” basically the same as “reasonable endeavours”?

In negotiations, parties often treat them as different levels of effort. In reality, how “hard” each standard is will depend on the drafting and context, and courts don’t apply a fixed hierarchy in every case. As a business-friendly rule of thumb:

• Reasonable endeavours: you must take sensible steps, but you typically don’t have to sacrifice your commercial interests or incur significant cost (especially if that’s not proportionate in context).
• All reasonable endeavours: you may have to try multiple reasonable routes (not just one), potentially spending more time and cost than “reasonable endeavours” - but there is still usually a reasonableness limit.
• Best endeavours: you may be expected to take all steps that are reasonably capable of being taken in the circumstances to achieve the objective, which can include time and cost - unless the contract limits this.

Because “best endeavours” can drift towards “do everything you reasonably can”, many small businesses prefer “reasonable endeavours” unless the obligation is clearly scoped and cost-capped.

If you’re deciding between “best endeavours” and “reasonable efforts” style wording, it can help to align the clause with a broader “what’s commercially reasonable” framework - the concept is explained clearly in Commercially Reasonable Efforts.

Common Trap: “Best Endeavours” With No Boundaries

A vague clause like this is where disputes start:

“The Supplier shall use its best endeavours to meet the Delivery Date.”

Questions that can follow include:

• Do you have to pay for premium shipping?
• Do you have to divert staff from other clients?
• Do you have to source from a more expensive supplier?
• Do you have to operate at a loss to hit the date?

If you don’t want those questions later, the contract should answer them upfront.

How To Draft A “Best Endeavours” Clause That Actually Protects Your Business

If you’re going to agree to “best endeavours”, the goal is simple: turn a fuzzy obligation into a practical checklist.

Here are the key drafting moves small businesses can use to make the clause clearer and safer.

1) Define The Objective (What Are You Trying To Achieve?)

Be specific about what the endeavours relate to. For example:

• obtaining a consent or approval
• meeting a target date
• fixing a defect
• achieving an integration milestone

The rest of the contract should also be consistent. If you’re mixing strict obligations with endeavours, double-check you’re not creating contradictory promises. (Clauses that override or carve out other clauses often appear as “notwithstanding” wording - if you see that a lot, it’s worth understanding what it does in Notwithstanding Clauses.)

2) List The Steps You Will (And Won’t) Be Required To Take

This is one of the most useful ways to prevent disputes.

For example, you can define “best endeavours” to include steps like:

• making applications within a set timeframe
• following up with the relevant third party at set intervals
• providing reasonable information requested
• arranging meetings promptly

And you can also explicitly exclude steps, such as:

• paying any fee above a stated cap
• litigating or appealing a decision
• agreeing to unusual conditions imposed by a third party
• breaching other contracts or laws

3) Add A Cost Cap Or “No Material Adverse Impact” Limitation

Small businesses often get caught by open-ended obligations. Consider language like:

• “provided that the Party is not required to incur costs exceeding £X”
• “provided that the Party is not required to take any step that would materially adversely affect its business”

These guardrails can make an endeavours clause feel much more proportionate.

4) Set A Timeframe And Reporting Obligations

“Best endeavours” can drag on indefinitely unless you define what “done” looks like.

Consider:

• a deadline for using endeavours (eg “for 60 days”)
• an escalation path if it’s not achieved (eg “senior representatives meet within 5 business days”)
• reporting (eg “weekly progress updates”)

5) Align The Clause With Your Contract’s Governing Law And Structure

Endeavours clauses are interpreted as part of the wider agreement, including dispute resolution clauses, definitions, and the governing law clause. If you’re cleaning up your boilerplate, it’s worth checking Governing Legislation is clearly set out.

Also, if you’re building or reviewing contracts more generally, a practical overview of the moving parts is in UK Contract Law - particularly around what happens if something goes wrong and remedies are sought.

“Best Endeavours” Clause Examples (Contract-Ready Templates)

Below are sample clauses to show what clearer “best endeavours” drafting can look like. These are examples only - you should tailor the wording to your deal, industry, and bargaining power.

Example 1: Best Endeavours With Clear Steps (Approvals)

“The Supplier shall use its best endeavours to obtain the Manufacturer’s written approval for the Product Specifications, including by: (a) submitting the application within 5 Business Days of the Effective Date; (b) responding promptly to reasonable requests for information; and (c) following up at least weekly. The Supplier is not required to commence legal proceedings or incur third-party fees exceeding £500 (excluding VAT) in performing this obligation.”

This is often a more “small-business-safe” way to use best endeavours: you still commit to trying hard, but you define what that means and cap the spend.

Example 2: Best Endeavours For Delivery Dates (With Alternatives)

“The Provider shall use its best endeavours to deliver the Services by the Delivery Date. If the Provider reasonably anticipates delay, it must notify the Customer as soon as practicable and propose an alternative delivery schedule. The Provider is not required to allocate additional resources where doing so would materially adversely affect its ability to meet obligations to other customers.”

This kind of drafting recognises a real-world issue for small businesses: you can’t always drop everything else for one contract.

Example 3: Best Endeavours In A Collaboration / Referral Arrangement

“Each party shall use its best endeavours to promote the Campaign during the Term, including by publishing at least two (2) posts per month on its primary social media channel(s). For the avoidance of doubt, neither party guarantees a minimum number of leads, sales, or conversions.”

If you’ve ever been in a partnership where one side felt the other “did nothing”, setting minimum activities can save a lot of friction.

Example 4: Best Endeavours With Consequences (But Not A Blank Cheque)

“The Company shall use its best endeavours to rectify any Critical Defect within 2 Business Days of notification. If the Company is unable to rectify the Critical Defect within that timeframe, it shall provide a workaround as soon as reasonably practicable. Any service credits set out in Schedule 2 apply without prejudice to the Customer’s other rights and remedies, except to the extent the parties validly agree otherwise under this Agreement.”

When you add consequences, you should also ensure your remedies and liability position make sense overall. “Sole remedy” wording, in particular, can be high-impact and needs careful legal review to make sure it is enforceable and consistent with the rest of the contract. For many businesses, the next step is checking whether your caps and exclusions are doing what you think they are - practical examples are set out in Limitation Of Liability.

More broadly, it’s wise to sense-check your key clauses as a package - especially payment, termination, liability, and dispute resolution - which are the kinds of provisions covered in Crucial Clauses.

When Should Your Business Use “Best Endeavours” (And When Should You Avoid It)?

“Best endeavours” isn’t automatically bad. In the right contract, it can be a practical compromise where nobody wants to promise a result they can’t fully control.

Situations Where “Best Endeavours” Can Make Sense

• Third-party approvals: landlord consent, planning permission, regulator approvals, platform approvals.
• Complex projects: integrations, staged deliverables, dependencies on multiple stakeholders.
• Joint marketing: where both parties can commit to effort-based activities (posts, outreach, events) rather than guaranteeing outcomes.

Situations Where You Might Push Back

• Critical delivery promises where you need certainty and control (you might prefer a clear service level with defined remedies instead).
• High-cost obligations that could spiral (unless you set a cost cap).
• Vague “best endeavours” language with no timeframe, no steps, and no limits.

If the other side insists on “best endeavours”, you don’t necessarily have to walk away - but you should tighten it so it’s workable for your business in practice.

Key Takeaways

• “Best endeavours” is an effort-based obligation commonly used where outcomes depend on third parties or uncertain conditions.
• For small businesses, “best endeavours” can be risky if it’s vague - disputes often focus on whether you tried hard enough, not just the end result.
• Use clear drafting: define the objective, list required steps, and add sensible limits (like a cost cap, time limit, and exclusions).
• If you need certainty, consider whether “reasonable endeavours” or a more structured SLA/remedies approach is a better fit than “best endeavours”.
• In customer comms, “best endeavours in a sentence” usually works best when paired with qualifiers (eg “subject to availability”) so you don’t accidentally overpromise.

If you’d like help reviewing or drafting a contract with a best endeavours clause (so you’re protected from day one), you can reach us at 08081347754 or team@sprintlaw.co.uk for a free, no-obligations chat.