Apply Conditional Validation with Validator::sometimes()

Use Validator::sometimes() to apply validation rules only when a specific input field is present or when a custom closure returns true.

When validating API endpoints or multi-step checkout forms, certain validation rules should only trigger when specific fields are present in the request payload or when particular business conditions are met.

Validating Fields Only When Present

Using sometimes as a rule string tells Laravel to only validate the field if it exists in the input array:

$request->validate([
    'email' => 'required|email',
    'password' => 'required|min:8',
    // Only validated if 'avatar' is present in request
    'avatar' => 'sometimes|image|max:2048',
]);

Dynamic Conditionals via Closure

To validate a field based on dynamic runtime logic, invoke sometimes() on the validator instance:

use Illuminate\Support\Facades\Validator;
use IlluminateValidationValidator as ValidatorInstance;

$validator = Validator::make($request->all(), [
    'email' => 'required|email',
    'channel' => 'required|in:email,sms',
]);

// Require phone_number only when channel is 'sms'
$validator->sometimes('phone_number', 'required|digits:10', function ($input) {
    return $input->channel === 'sms';
});

Summary

• sometimes rule string runs validation only when the attribute key exists in the input array.
• Validator::sometimes('field', 'rules', fn ($input) => ...) evaluates runtime logic to determine rule application.
• Ideal for flexible API PATCH endpoints and conditional checkout workflows.