Apply Conditional Validation Rules Cleanly with Rule::when() and Rule::excludeIf()

Use Rule::when() and Rule::excludeIf() to apply dynamic validation rules without writing fragmented if-else statements.

Complex forms often require fields to be validated or omitted based on other input values (such as requiring a tax ID only for business accounts, or excluding shipping fields for digital items).

Instead of manipulating rule arrays conditionally with nested if blocks, Laravel provides declarative rule helpers.

Conditional Validation with Rule::when()

use Illuminate\Validation\Rule;

public function rules(): array
{
    return [
        'account_type' => ['required', 'in:individual,business'],

        // Required and verified only if account_type is 'business'
        'tax_id' => [
            Rule::when(
                $this->account_type === 'business',
                ['required', 'string', 'max:20'],
                ['nullable', 'string']
            ),
        ],
    ];
}

Excluding Fields from Validated Output with Rule::excludeIf()

When optional fields are submitted but irrelevant (such as credit card details when paying with PayPal), Rule::excludeIf() strips the field from $request->validated():

use Illuminate\Validation\Rule;

public function rules(): array
{
    return [
        'payment_method' => ['required', 'in:card,paypal'],

        // Completely excluded from $request->validated() when payment_method is paypal
        'card_number' => [
            Rule::excludeIf($this->payment_method === 'paypal'),
            'required',
            'numeric',
        ],
    ];
}

Summary

• Rule::when($condition, $rules, $defaultRules) swaps rules dynamically based on booleans or closures.
• Rule::excludeIf($condition) omits fields from the final validated data payload when true.
• Keeps form request classes declarative and easy to read.