fix(phone-input): add Austria mask and prevent double plus prefix

[abhayymishraa]

What does this PR do?

This PR improves the PhoneInput component by addressing inconsistent phone number formatting and user experience issues:

1. Added Austria mask - Adds a custom phone mask for Austria (at) to improve number grouping from the odd default +43 123 456789 to a cleaner +43 XXX XXX XXXX format
2. Prevents double plus prefix - Modified the onChange handler to check if the value already starts with + before prepending it, preventing issues like ++1234567890 when users paste numbers that already include the prefix

• Fixes Inconsistent Phone Number Formatting Across Country Codes in PhoneInput Component #24193
• Fixes CAL-6497

Visual Demo (For contributors especially)

A visual demonstration is strongly recommended, for both the original and new change (video / image - any one).

Video Demo (if applicable):

Fixed the issue:

Screen.Recording.2026-01-09.at.10.12.59.PM.mov

Mandatory Tasks (DO NOT REMOVE)

• I have self-reviewed the code (A decent size PR without self-review might be rejected).
• I have updated the developer docs in /docs if this PR makes changes that would require a documentation change. If N/A, write N/A here and check the checkbox.
• I confirm automated tests are in place that prove my fix is effective or that my feature works.

How should this be tested?

Test the Austria Mask:

1. Start the dev server: yarn dev
2. Navigate to Event Types → Edit any event type
3. Go to Advanced tab → Add Phone Number question → Save
4. Click Preview to open the booking page
5. In the phone input, select Austria (+43) from the country dropdown
6. Type: 6601234567
7. Expected: Numbers should be grouped as 660 123 4567

Test the Double Plus Prevention:

1. In the same phone input
2. Copy and paste: +436601234567
3. Expected: Should display correctly, NOT as ++436601234567

Checklist

[vercel]

@abhayymishraa is attempting to deploy a commit to the cal-staging Team on Vercel.

A member of the Team first needs to authorize it.

[cubic-dev-ai]

1 issue found across 1 file

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="packages/features/components/phone-input/PhoneInput.tsx">

<violation number="1" location="packages/features/components/phone-input/PhoneInput.tsx:84">
P1: The double plus prevention fix is incomplete. `BasePhoneInputWeb` (line 128) still uses the old pattern `onChange(\`+${val}\`)` and will produce `++` when users paste numbers with the prefix. Consider applying the same fix to maintain consistency.</violation>
</file>

_{Reply with feedback, questions, or to request a fix. Tag @cubic-dev-ai to re-run a review.}

[abhayymishraa]

@pallava-joshi @dhairyashiil could you take a look into it?

[anikdhabal]

@@cubic-dev-ai can you pls review the changes again?

[cubic-dev-ai]

@@cubic-dev-ai can you pls review the changes again?

@anikdhabal I have started the AI code review. It will take a few minutes to complete.

[cubic-dev-ai]

No issues found across 1 file