Phone Number Block - Flex Forms

The Phone Number block is an advanced input field that abstracts away the complexity of global phone formats. It automatically handles country dialing codes, validates number lengths based on the selected country, and standardizes the output for your CRM or SMS gateways.

Business Use Cases

SMS Marketing

Collect verified mobile numbers to send promotional blasts or event reminders.

Sales Outreach

Ensure your sales team gets perfectly formatted international numbers to dial right from their CRM.

Two-Factor Auth

Capture mobile-only numbers required for sending 2FA security codes.

Configuration & Usage

Deploy to Canvas

Drag the Phone block from the Component Catalog onto the Canvas.

Configure Default Locale

Set your Default Country. This determines which flag and dialing code (e.g., +1 for US) is selected when the user opens the form.

Restrict Geographies (Optional)

If you only do business in Europe, use the Countries array to whitelist specific nations, preventing users from submitting numbers from unsupported regions.

Technical Configuration Schemas

Visuals & UI
Geographic Restrictions
Validation Rules

string

default:"md"

The visual size of the phone input. Available options are sm, md, and lg.

string

default:"PL"

The ISO 3166-1 alpha-2 country code (e.g., US, PL, GB) selected by default.

boolean

default:"false"

Enables a search bar inside the country flag dropdown, allowing users to quickly find their nation.

boolean

default:"false"

If enabled, the field enforces the + prefix natively in the UI.

Data Payload Architecture

Regardless of how messy the user types their number, the Phone block strips all formatting and converts it into the globally recognized E.164 standard.

{
  "submission_id": "sub_902",
  "data": {
    "customer_phone": "+48123456789"
  }
}

[
    'customer_phone' => '+48123456789',
]

Deep Dive: E.164 Standardization

Phone numbers are notoriously messy. Users might type (555) 123-4567, 5551234567, or +1 555-123-4567. If you attempt to send an SMS via Twilio or sync this data to Salesforce, formatting inconsistencies will cause catastrophic failures.

E.164 Guarantee: Because Flex Forms handles this normalization before the data is saved, your integrations will never fail due to a malformed phone number.

Best Practices & FAQs

Enforcing Mobile Only

If your workflow involves sending a 2FA code or marketing SMS after submission, you must enable Mobile Only. This prevents users from entering a landline number that cannot receive text messages, which would break your flow.

Using Searchable Flags

If you allow all global countries (not whitelisting), always enable Searchable. Scrolling through 195+ flags on a mobile device is a terrible user experience.

​Business Use Cases

SMS Marketing

Sales Outreach

Two-Factor Auth

​Configuration & Usage

​Technical Configuration Schemas

​Data Payload Architecture

​Deep Dive: E.164 Standardization

​Best Practices & FAQs

Business Use Cases

Configuration & Usage

Technical Configuration Schemas

Data Payload Architecture

Deep Dive: E.164 Standardization

Best Practices & FAQs