Sneaking · Australia

Negative option or unauthorised transaction

Negative option or unauthorised transaction is a working label for this design mechanism: Silence, inactivity or an ineffective prior interaction is treated as authorisation for a paid or consequential transaction. This is editorial implementation guidance for Australian journeys, not a finding of unlawfulness. From 1 July 2027, a similar interface is relevant to ACL section 28B only if the complete consumer-connection, manipulation or unreasonable-distortion and actual-or-likely-detriment test is met. Current ACL rules require a separate assessment.

Editorial implementation guidance
Family
Sneaking
Also known as
  • inertia selling
  • silence as consent
  • unauthorised renewal
  • charge unless user opts out
  • paid conversion without valid assent
  • post-trial transaction without effective notice
  • service supplied and billed without request

Definition

What is this pattern?

Silence, inactivity or an ineffective prior interaction is treated as authorisation for a paid or consequential transaction. This is a design and research taxonomy for learning and evidence review, not a statutory offence label or an automatic finding that an interface is unlawful.

How it works

Silence, inactivity or an ineffective prior interaction is treated as authorisation for a paid or consequential transaction. Silence, a failed refusal or another non-affirmative event is interpreted as permission for a new charge, product or continuing commercial state.

Warning signs

  • A charge, supply or commitment occurs or is scheduled.
  • No clear current assent to that consequence is evidenced.
  • The design relies on non-response, hidden default or ambiguous prior wording.

Potential harms

  • Inactivity may produce a charge that the subscriber never actively authorised.
  • A person can be charged despite attempting to refuse the transaction through the supplied route.

Learn by comparison

What does this look like?

These fictional examples make the design mechanism easier to recognise. They do not depict a real company and do not establish that an individual interface is unlawful.

Illustrative example 1 · Silence treated as renewal approval

A fictional service states that failing to reply to an email will be treated as approval for a new paid add-on at renewal.

Potential consumer harm: Inactivity may produce a charge that the subscriber never actively authorised.

Illustrative example 2 · Broken opt-out still results in a charge

A fictional trial email provides an opt-out link that returns an error, then charges the customer because the failed request is recorded as no response.

Potential consumer harm: A person can be charged despite attempting to refuse the transaction through the supplied route.

What is a fairer alternative?

Obtain clear, specific assent before any paid consequence and do not treat silence or inactivity as a new authorisation.

Context matters

Context and boundary cases

  • A charge, supply or commitment occurs or is scheduled.
  • No clear current assent to that consequence is evidenced.
  • The design relies on non-response, hidden default or ambiguous prior wording.
  • Boundary to test: Clearly disclosed subscription renewal supported by valid assent and applicable notices
  • Boundary to test: transaction explicitly confirmed at the material decision point
  • Boundary to test: purely free continuation with no material consequence

When a similar design can serve a legitimate purpose

  • Clearly disclosed subscription renewal supported by valid assent and applicable notices
  • transaction explicitly confirmed at the material decision point
  • purely free continuation with no material consequence

Operational review

What teams should review

Teams
  • Product
  • Design
  • Engineering
  • Legal
  • Compliance
  1. Which affirmative action authorises “No action means yes”, and where is the resulting price, product or recurring state shown before commitment?
  2. Capture every peer option, its default state and visual prominence; do those states support “A charge, supply or commitment occurs or is scheduled”?
  3. Which specific affirmative event creates the final commercial state, and could “Clearly disclosed subscription renewal supported by valid assent and applicable notices” explain the observed outcome instead?
  4. Which affirmative action authorises “No response recorded”, and where is the resulting price, product or recurring state shown before commitment?
  5. Count steps, waits, offers and channel changes through final confirmation; where does the route meet “No clear current assent to that consequence is evidenced”?
  6. Which specific affirmative event creates the final commercial state, and could “transaction explicitly confirmed at the material decision point” explain the observed outcome instead?

Evidence to retain

  • Annotated subscription and cancellation screenshots at each responsive breakpoint
  • The complete state sequence before, during and after the consumer decision
  • Design-system component, content, default and configuration records for the reviewed release
  • Operational records substantiating price, availability, timing and eligibility claims
  • Usability, accessibility, reversal, complaint and support evidence relevant to consumer impact
  • A dated product and legal review record identifying evidence, uncertainties and release decisions

Legal map and implementation tools

Evidence base

Sources

  1. An Ontology of Dark Patterns KnowledgeGray et al.; ACM CHI 2024 · Secondary · checked 2026-09-14 · DOI 10.1145/3613904.3642436; arXiv:2309.09640
  2. Competition and Consumer Amendment (Unfair Trading Practices) Act 2026Federal Register of Legislation · Primary · checked 2026-09-14 · C2026A00064
  3. Competition and Consumer Act 2010, including Schedule 2: Australian Consumer LawFederal Register of Legislation · Primary · checked 2026-09-14 · C2004A00109
  4. Unfair trading tricks and traps to be bannedTreasury Ministers · Primary · checked 2026-09-14
  5. Inquiry into the Competition and Consumer Amendment (Unfair Trading Practices) Bill 2026Senate Economics Legislation Committee · Primary · checked 2026-08-09