Ambiguous contractual terms can create disputes over liability, particularly where one party seeks to rely on an exclusion, limitation or indemnity clause. Australian contract law recognises the contra proferentem rule, under which unresolved ambiguity may be construed against the party putting forward or seeking to rely on the relevant contractual provision. However, the rule operates only as a last resort. Understanding its application can help businesses manage contractual risk and avoid disputes arising from unclear drafting.
What is the contra proferentem rule?
Contra proferentem is a Latin expression meaning “against the party putting forward the wording”. In circumstances where a contractual provision remains genuinely ambiguous after ordinary principles of interpretation have been applied, a court may adopt the meaning less favourable to the party putting forward or seeking to rely on that provision. The principle reflects the view that a party responsible for advancing particular contractual terms may bear the consequences of unresolved uncertainty in their meaning. However, the rule does not automatically operate against the party who physically drafted the contract. The identity of the proferens depends on the clause and contractual circumstances.
When will Australian courts apply the rule?
Australian courts first interpret contracts objectively, considering their language, context and commercial purpose. In Mount Bruce Mining Pty Ltd v Wright Prospecting Pty Ltd [2015] HCA 37, [46]-[51], the High Court confirmed that commercial contracts should be interpreted according to what a reasonable businessperson would understand their terms to mean.
In Darlington Futures Ltd v Delco Australia Pty Ltd (1986) 161 CLR 500, 510-511, the High Court held that exclusion and limitation clauses should be given their natural and ordinary meaning, having regard to the contract as a whole. The contra proferentem rule may assist where ambiguity remains, but does not justify an artificially restrictive interpretation.
More recently, the Full Federal Court confirmed that the rule operates as a last resort in LCA Marrickville Pty Ltd v Swiss Re International SE [2022] FCAFC 17, [96]-[103]. It applies only where ordinary principles of interpretation leave uncertainty between available constructions.
Accordingly, a contractual provision will not automatically be interpreted against the party responsible for its wording merely because another interpretation is arguable.
Which contractual clauses are most affected?
The rule is particularly relevant to provisions allocating liability and commercial risk.
Exclusion and limitation clauses
These clauses seek to exclude liability or limit the amount recoverable following a breach or other specified event. For example, where a service agreement excludes liability for ‘loss arising from delays’, uncertainty may arise over whether the exclusion extends to particular financial losses. Courts will first examine the wording and contractual context before considering whether unresolved ambiguity should be construed against the party relying on the clause.
Indemnity clauses Indemnities generally require one party to compensate another for specified losses or liabilities. In Andar Transport Pty Ltd v Brambles Ltd [2004] HCA 28, [17]-[23], [29], the High Court considered the interpretation of contractual indemnities. The majority held that, to the extent ambiguity remained, the relevant provisions should be construed in favour of the indemnifier, who would otherwise bear the additional liability. This does not mean that all indemnities must automatically be interpreted against the party benefiting from them.
Insurance contracts The rule may also arise where an insurance policy contains ambiguous coverage or exclusion provisions. In LCA Marrickville, the Full Federal Court considered the rule in the context of insurance policies and confirmed that ordinary principles of contractual interpretation must first be applied. An exclusion clause is not automatically interpreted narrowly merely because it favours the insurer.
How does the rule interact with unfair contract terms law?
The contra proferentem rule is distinct from Australia's statutory unfair contract terms regime. Under sections 23-28 of the Australian Consumer Law, contained in Schedule 2 to the Competition and Consumer Act 2010 (Cth), unfair terms in qualifying standard form consumer and small business contracts may be void.
Since 9 November 2023, subject to applicable transitional provisions, proposing, applying or relying on prohibited unfair contract terms can also attract civil penalties. While contra proferentem addresses unresolved ambiguity in contractual interpretation, unfair contract terms legislation concerns whether a provision satisfies statutory requirements for fairness and enforceability. A clearly drafted clause may therefore still be unfair under the legislation, while an ambiguous clause is not necessarily unfair.
What should businesses consider when drafting contracts?
Businesses should review contractual provisions allocating liability, financial risk and other obligations before entering into agreements. Particular attention should be given to:
- Exclusions and limitations: Clearly identify the liabilities, losses and circumstances covered.
- Indemnities: Define the scope of indemnified losses, relevant parties and applicable limitations.
- Consistent terminology: Use clear definitions and avoid conflicting or overlapping provisions.
- Contractual context: Ensure individual clauses operate consistently with the agreement's commercial purpose and intended allocation of risk.
Businesses using standard form agreements should also consider compliance with applicable unfair contract terms legislation.
Clear drafting and early legal review can reduce uncertainty, strengthen contractual risk allocation and minimise the likelihood of disputes.
References:
- Mount Bruce Mining Pty Ltd v Wright Prospecting Pty Ltd [2015] HCA 37, [46]-[51].
- Darlington Futures Ltd v Delco Australia Pty Ltd (1986) 161 CLR 500, 510-511.
- LCA Marrickville Pty Ltd v Swiss Re International SE [2022] FCAFC 17, [96]-[103].
- Andar Transport Pty Ltd v Brambles Ltd [2004] HCA 28, [17]-[23], [29].
- Competition and Consumer Act 2010 (Cth) sch 2 (‘Australian Consumer Law’) ss 23-28.