Short answer
A UK employment contract is not confined to one signed document. Its terms may be written, oral, incorporated from a handbook or collective agreement, required by statute, implied by law or fact, or inferred from a sufficiently certain and well-understood practice. The written statement required by the Employment Rights Act 1996 is important evidence, but is not necessarily the whole contract.
A collective agreement is normally presumed not to be enforceable as a contract between the union and employer. Even so, suitable provisions—especially pay, hours and holidays—can become binding terms of individual employment contracts through express or implied incorporation. A workplace practice becomes contractual only when the employer has objectively communicated that employees receive the benefit as of right, not merely by discretion.
During employment, implied duties include fidelity, reasonable care, obedience to lawful instructions, confidentiality and mutual trust and confidence. After employment, express confidentiality and restrictive covenants may protect trade secrets, customer connections and workforce stability, but cannot simply suppress competition or statutory disclosures. Enforceability turns on construction, legitimate interest, necessity, proportionality and the circumstances when the covenant was agreed.
Map every possible source of terms
Start with the offer and written contract, then examine:
- the statutory written statement, variation letters and side agreements;
- policies, handbooks, bonus rules and benefit-plan documents;
- collective agreements;
- oral assurances and recruitment communications;
- legislation;
- established workplace practices; and
- terms implied in fact or by law.
requires prescribed particulars, including reference to collective agreements directly affecting the work. Omitting a term does not prevent it being contractual; including a policy does not make every detail binding. Courts construe documents and conduct objectively, including whether a provision is apt for individual enforcement.
Statutory minimum rights override less favourable terms. An express term usually defeats an inconsistent alleged custom or fact-implied term, but it cannot contract out of protected employment rights unless legislation permits a valid settlement route.
Collective agreements operate at two levels
conclusively presumes that a collective agreement was not intended to be legally enforceable between its parties unless it is written and expressly states otherwise. This promotes collective resolution rather than ordinary contract litigation between union and employer.
The separate question is whether a collective provision has entered an employee's individual contract. Express wording may incorporate the agreement as amended from time to time. Incorporation may also be inferred where the provision is individually applicable, certain and consistently treated as binding. Pay scales, overtime, hours and leave are more readily incorporated than collective machinery, negotiating procedures or aspirational commitments.
Identify the bargaining unit, agreement version, recognition status and contractual wording. A clause allowing collectively agreed changes can authorise a union to bind employees, but its scope requires careful construction. TUPE can carry incorporated terms and collective-agreement effects to a transferee under special rules.
Employers also face statutory limits when approaching workers directly. prohibit offers whose sole or main purpose is to achieve the “prohibited result” that terms will not, or will no longer, be determined by collective agreement. In , direct offers made before the agreed collective process was exhausted infringed section 145B. A genuine direct offer after collective bargaining has been followed and exhausted is different from bypassing it.
Custom and practice requires an objective contractual commitment
Repetition alone does not turn generosity into legal obligation. The question is what the employer's words and conduct reasonably communicated to the workforce. Relevant factors include frequency and duration, consistency, certainty of amount or method, workforce knowledge, communications, whether payment was automatic, and any express reservation of discretion.
In , employees claimed enhanced redundancy terms from past payments. The Court said the terminology should not obscure the contractual inquiry:
“the essential object is to ascertain what the parties must have, or must be taken to have, understood from each other's conduct and words”
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The practical question is whether the employer conveyed an intention to confer the benefit as of right. Variable, exceptional or individually negotiated payments point away from a term. A clear non-contractual reservation also matters, although a disclaimer added after a term has already arisen cannot retrospectively remove it.
Implied duties fill necessary gaps but do not rewrite the bargain
Terms may be implied because they are necessary for the contract's operation, so obvious that both parties must have intended them, or incidents imposed by law on employment relationships. The threshold is demanding: implication does not permit a court to make the contract fairer or contradict express language.
Employees ordinarily owe duties of faithful service, reasonable skill and care, obedience to lawful and reasonable orders, accounting for the employer's property, and confidentiality. Some senior employees or directors may owe fiduciary duties, but fiduciary status is not automatic for every employee.
Employers owe duties including payment, reasonable care for health and safety, cooperation, and not acting without reasonable and proper cause in a manner calculated or likely seriously to damage trust and confidence. A fundamental breach may entitle the employee to resign and claim constructive dismissal, subject to status, causation and statutory conditions. The implied trust term does not create a general duty to dismiss only reasonably or circumvent the statutory unfair-dismissal scheme.
Good faith is therefore specific, not an unlimited power to review workplace decisions. Discretionary bonuses, mobility and flexibility clauses must be exercised within their wording, for proper purposes and consistently with implied constraints, but courts do not replace a genuine discretion with their preferred outcome.
Restrictive covenants are presumptively void unless justified
Post-termination non-compete, non-solicitation, non-dealing and non-poaching clauses restrain trade. The employer must show a legitimate proprietary interest and that the clause goes no further than reasonably necessary between the parties and in the public interest. Legitimate interests can include trade secrets, confidential information, customer connections and workforce stability—not freedom from ordinary competition or loss of an employee's general skill.
Reasonableness is assessed when the covenant was agreed, considering role, influence, information, customers, geography, activities and duration. Narrow non-solicitation or confidentiality protection may make a blanket non-compete unnecessary.
In , a non-compete improperly prohibited even a minor shareholding. The Supreme Court allowed severance of the offending words where removal required no addition or modification, the remaining promises were supported, and severance did not materially change the overall effect. Courts do not generally redraft an unreasonable covenant; careful drafting remains decisive.
“all restraints of trade were presumed to be bad but that the presumption was rebuttable”
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The government announced an intention in 2023 to legislate for a three-month non-compete limit, but as at 19 July 2026 no general statutory cap is in force. Current common-law enforceability must therefore be assessed rather than assuming the proposed cap applies.
Confidentiality during and after employment
During employment, the implied duty of fidelity protects confidential business information more broadly. After termination, the implied duty generally protects trade secrets and information of equivalent confidentiality, not the employee's general skill, experience or information that has become public. An express clause may extend protection, but must define a legitimate confidential interest and cannot operate as an unreasonable disguised restraint of trade.
The provide definitions, limitation rules and remedies for unlawful acquisition, use or disclosure while preserving broader UK remedies where lawful. Evidence should show secrecy measures: access controls, marking, policies, training, technical safeguards and prompt response. Merely labelling everything “confidential” is weak.
No confidentiality clause can lawfully preclude a protected whistleblowing disclosure: makes such a provision void. Clauses must also accommodate lawful reporting to police, regulators, professional advisers and other protected channels. The Employment Rights Act 2025 contains further rules voiding provisions that suppress allegations or disclosures about workplace harassment or discrimination, but regulations defining exceptions and commencement are scheduled for 2027. They should not be represented as already operative in July 2026.
Enforcement and practical drafting
Remedies include injunctions, delivery up or deletion, damages, an account in suitable cases and costs. Urgency and evidence matter; delay can defeat practical relief. Garden leave can protect interests while employment and pay continue, subject to its interaction with post-termination restrictions.
Drafting should separate confidential information, intellectual property, notice, garden leave and each restrictive covenant; tailor restrictions to role and access; state which policies are contractual; identify incorporation and variation mechanisms; and preserve statutory disclosures. On exit, record devices, accounts, downloads, customers and return or deletion of information without unlawfully monitoring the worker.
Conclusion
UK employment terms arise from a hierarchy of agreement, incorporation, statute, implication and proven practice. Collective provisions can bind individuals even where the union-employer agreement itself is non-enforceable; custom depends on communicated entitlement, not repetition alone. Implied duties protect the relationship while respecting express terms. After termination, confidentiality and covenants protect legitimate interests only to a reasonable extent and never override whistleblowing or other mandatory rights.
Sources
This article provides general legal information, not advice for a specific matter. Laws, facts and procedural deadlines may change the result. Follow the linked primary sources and obtain local advice before acting.