set code title references 4 402 Payment Required .NET HTTP Status Enum Rust HTTP Status Constant Rails HTTP Status Symbol Go HTTP Status Constant Symfony HTTP Status Constant Python2 HTTP Status Constant Python3+ HTTP Status Constant Python3.5+ HTTP Status Constant HttpStatusCode.PaymentRequired http::StatusCode::PAYMENT_REQUIRED :payment_required http.StatusPaymentRequired Response::HTTP_PAYMENT_REQUIRED httplib.PAYMENT_REQUIRED http.client.PAYMENT_REQUIRED http.HTTPStatus.PAYMENT_REQUIRED Reserved for future use. Source: RFC7231 Section 6.5.2