Feature Flaw: Duplicate Phone Numbers not handled.

[devivy]

2 users cannot have the same phone number. However, When I add in 2 users with the same phone number, No error message was given.

[nus-pe-bot]

Team's Response

Hi tester, this was intentional, as there can be multiple contacts that are reached via the same phone number, e.g. a company customer service hotline or if you are a private tutor who teaches siblings, then the phone number would be the same parent if each contact represents a student. Some buildings can also have the same landline / hotline number, but different extensions, which may not be disclosed to the user.

Thank you.

Items for the Tester to Verify

:question: Issue response

Team chose [response.Rejected]

• [x] I disagree

Reason for disagreement: Reason for Disagreement:

Dear Dev Team,

I respectfully but strongly disagree with accepting duplicate phone numbers as intentional behaviour. Here's why:

Edge Cases vs. Data Integrity: -Your examples (company hotlines, siblings, building numbers) are edge cases. -Designing core validation around edge cases creates larger risks. -These scenarios should be handled through proper data modelling, not by compromising basic validation.

Current Implementation Risks: -No way to distinguish between legitimate shared numbers and data entry errors. -No warning/confirmation when entering duplicate numbers. -No visual indication that a number is shared across contacts. -No way to bulk-update shared numbers if the main number changes.

Industry Standard Practice: -Major contact management systems (Salesforce, HubSpot) don't allow duplicate numbers by default -They handle shared numbers through proper data structures -This is because phone validation is a fundamental data integrity requirement

Thank you.

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## :question: Issue severity Team chose [`severity.Low`] Originally [`severity.Medium`] - [ ] I disagree **Reason for disagreement:** [replace this with your explanation]

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