Sneaking · Australia
Bait and switch
Bait and switch is a working label for this design mechanism: The user selects a represented action or offer but receives a materially different outcome that favours the business. 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.
- Family
- Sneaking
- Also known as
- Journey stages
Definition
What is this pattern?
The user selects a represented action or offer but receives a materially different outcome that favours the business. 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
The user selects a represented action or offer but receives a materially different outcome that favours the business. The activated control produces a materially different product, price or action from the one its label and preceding selection represented.
Warning signs
- The pre-action representation supports a reasonably specific expected outcome.
- The observed post-action state materially differs from that outcome.
- The mismatch is not corrected before commitment and favours the business.
Potential harms
- The user receives a materially different action from the one represented and may install unwanted software.
- The traveller may buy a different, more expensive product than the one selected.
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 · Download control opens an unrelated installer
A fictional account page labels a prominent control “Download document”, but it launches an optional browser-extension installer instead.
Potential consumer harm: The user receives a materially different action from the one represented and may install unwanted software.
Illustrative example 2 · Selected basic fare changes at confirmation
A fictional booking flow records a basic fare selection but the final action purchases a premium flexible fare without a new price-and-product confirmation.
Potential consumer harm: The traveller may buy a different, more expensive product than the one selected.
Download control opens an unrelated installer
A fictional account page labels a prominent control “Download document”, but it launches an optional browser-extension installer instead.
Download your document. The prominent control starts an extension installer instead of the file.. Download now. Download PDF
Your document is ready. The file action downloads the document; optional software is a separate offer.. Download PDF. Download now. What happens next, expanded: Activating “Download PDF” produces the outcome stated on the control.
Why the first version can mislead: The final commercial state diverges from the choice represented earlier in the journey. The problematic state records: “The prominent control starts an extension installer instead of the file.” Review the timing and affirmative selection needed before “Download now” changes price, product or recurring liability. The user receives a materially different action from the one represented and may install unwanted software.
What a fairer design does: Make the document action perform the stated download and label any optional software offer separately.
Show annotated differences (4)
- The prominent control starts an extension installer instead of the file.Why this state matters: The final commercial state diverges from the choice represented earlier in the journey. The problematic state records: “The prominent control starts an extension installer instead of the file.” Review the timing and affirmative selection needed before “Download now” changes price, product or recurring liability. The user receives a materially different action from the one represented and may install unwanted software.
- Download PDFReview prompt: Which affirmative action authorises “Download now”, and where is the resulting price, product or recurring state shown before commitment?
- The file action downloads the document; optional software is a separate offer.Fairer design: Make the document action perform the stated download and label any optional software offer separately.
- What happens next, expanded: Activating “Download PDF” produces the outcome stated on the control.Review prompt: Can the dialog be dismissed, what action does each control trigger, and what later state confirms or contradicts “The pre-action representation supports a reasonably specific expected outcome”?
Review questions (3)
- Which affirmative action authorises “Download now”, and where is the resulting price, product or recurring state shown before commitment?
- Can the dialog be dismissed, what action does each control trigger, and what later state confirms or contradicts “The pre-action representation supports a reasonably specific expected outcome”?
- Which specific affirmative event creates the final commercial state, and could “Clearly disclosed intermediate step” explain the observed outcome instead?
Selected basic fare changes at confirmation
A fictional booking flow records a basic fare selection but the final action purchases a premium flexible fare without a new price-and-product confirmation.
Complete booking. The final summary silently substitutes the premium fare.. Amount affected: $240. Pay $240. Book basic fare $160
Basic fare selected. The fare, conditions and $160 total match the earlier choice.. Amount affected: $160. Book basic fare $160. Pay $240. Payable total and selected items, expanded: The summary shows the line items and total before “Book basic fare $160” is activated.
Why the first version can mislead: The final commercial state diverges from the choice represented earlier in the journey. The problematic state records: “The final summary silently substitutes the premium fare.” Review the timing and affirmative selection needed before “Pay $240” changes price, product or recurring liability. The traveller may buy a different, more expensive product than the one selected.
What a fairer design does: Preserve the selected fare and require explicit review if availability requires a different product or price.
Show annotated differences (4)
- The final summary silently substitutes the premium fare.Why this state matters: The final commercial state diverges from the choice represented earlier in the journey. The problematic state records: “The final summary silently substitutes the premium fare.” Review the timing and affirmative selection needed before “Pay $240” changes price, product or recurring liability. The traveller may buy a different, more expensive product than the one selected.
- Book basic fare $160Review prompt: Which affirmative action authorises “Pay $240”, and where is the resulting price, product or recurring state shown before commitment?
- The fare, conditions and $160 total match the earlier choice.Fairer design: Preserve the selected fare and require explicit review if availability requires a different product or price.
- Payable total and selected items, expanded: The summary shows the line items and total before “Book basic fare $160” is activated.Review prompt: Compare the basket before and after the action, including total and line items; does the mutation satisfy “The observed post-action state materially differs from that outcome”?
Review questions (3)
- Which affirmative action authorises “Pay $240”, and where is the resulting price, product or recurring state shown before commitment?
- Compare the basket before and after the action, including total and line items; does the mutation satisfy “The observed post-action state materially differs from that outcome”?
- Which specific affirmative event creates the final commercial state, and could “availability change explained before commitment” explain the observed outcome instead?
What is a fairer alternative?
Make the action produce its represented result or disclose and obtain assent to any material change before commitment.
Legal and information status
How Australian law may apply
The user selects a represented action or offer but receives a materially different outcome that favours the business. The activated control produces a materially different product, price or action from the one its label and preceding selection represented. These harms describe a review risk, not an automatic legal conclusion. Australian section 28B commences on 1 July 2027 and requires its complete, context-specific test. Existing ACL provisions remain a separate current-law assessment.
ACL section 28B, inserted by the 2026 Act
Possible risk indicator
In account management and checkout journeys, the bait and switch mechanism may warrant review where it manipulates a consumer or unreasonably distorts the decision environment and causes, or is likely to cause, detriment. The sneaking label and an interface similarity do not establish a contravention; the complete section 28B test, scope, facts and evidence must be applied from 1 July 2027.
Dark-pattern research taxonomy
Editorial analysis
The cited research sources support this working pattern within the sneaking family. It is editorial implementation guidance, not an Australian statutory category, regulator finding or legal safe harbour.
Evidence layers and open questions
Applicable law, enforcement records, policy preparation, stakeholder input, editorial analysis and unknown future details remain visibly distinct.
Final Act mappingEditorial implementation guidance
This editorial practice label is not itself an express statutory prohibition. Apply the complete provision and its scope to the facts.
Possible general-test applicationCommences 1 July 2027
ACL section 28B, inserted by the 2026 Act: In account management and checkout journeys, the bait and switch mechanism may warrant review where it manipulates a consumer or unreasonably distorts the decision environment and causes, or is likely to cause, detriment. The sneaking label and an interface similarity do not establish a contravention; the complete section 28B test, scope, facts and evidence must be applied from 1 July 2027.
Existing ACLCurrent enforcement
Existing ACL provisions continue to apply on their own elements before and after commencement. The 2027 provisions must not be applied early.
Verified enforcement contextCurrent enforcement
No named pattern-specific enforcement example is asserted on this page. Existing ACL analysis remains fact-specific and separate from the 2027 provisions.
RegulationsRegulation pending
Later regulations may affect specified exclusions, matters or exceptions. That uncertainty does not postpone a core enacted rule unless the provision itself depends on prescription.
Regulator implementation materialGuidance pending
Government funding and parliamentary material anticipate regulator education and guidance. No dedicated final ACCC implementation guide is treated here as published.
Journey and evidence recommendationsEditorial implementation guidance
Make the action produce its represented result or disclose and obtain assent to any material change before commitment. This is editorial portal guidance, not a statutory duty, regulator safe harbour or compliance certificate.
Context matters
Context and boundary cases
- The pre-action representation supports a reasonably specific expected outcome.
- The observed post-action state materially differs from that outcome.
- The mismatch is not corrected before commitment and favours the business.
- Boundary to test: Clearly disclosed intermediate step
- Boundary to test: availability change explained before commitment
- Boundary to test: ordinary navigation label imprecision with no detriment
When a similar design can serve a legitimate purpose
- Clearly disclosed intermediate step
- availability change explained before commitment
- ordinary navigation label imprecision with no detriment
Operational review
What teams should review
- Teams
- Which affirmative action authorises “Download now”, and where is the resulting price, product or recurring state shown before commitment?
- Can the dialog be dismissed, what action does each control trigger, and what later state confirms or contradicts “The pre-action representation supports a reasonably specific expected outcome”?
- Which specific affirmative event creates the final commercial state, and could “Clearly disclosed intermediate step” explain the observed outcome instead?
- Which affirmative action authorises “Pay $240”, and where is the resulting price, product or recurring state shown before commitment?
- Compare the basket before and after the action, including total and line items; does the mutation satisfy “The observed post-action state materially differs from that outcome”?
- Which specific affirmative event creates the final commercial state, and could “availability change explained before commitment” explain the observed outcome instead?
Evidence to retain
- Annotated account management and checkout 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
- Dark commercial patternsOrganisation for Economic Co-operation and Development · Secondary · checked 2026-09-14 · OECD Digital Economy Papers No. 336
- Competition and Consumer Amendment (Unfair Trading Practices) Act 2026Federal Register of Legislation · Primary · checked 2026-09-14 · C2026A00064
- Competition and Consumer Act 2010, including Schedule 2: Australian Consumer LawFederal Register of Legislation · Primary · checked 2026-09-14 · C2004A00109
- Unfair trading tricks and traps to be bannedTreasury Ministers · Primary · checked 2026-09-14
- Inquiry into the Competition and Consumer Amendment (Unfair Trading Practices) Bill 2026Senate Economics Legislation Committee · Primary · checked 2026-08-09