diff --git a/authority/provisioner/scep.go b/authority/provisioner/scep.go
index 3e3e77b9..0c514275 100644
--- a/authority/provisioner/scep.go
+++ b/authority/provisioner/scep.go
@@ -196,8 +196,6 @@ func (c *notificationController) Success(ctx context.Context, csr *x509.Certific
 			return fmt.Errorf("failed creating new webhook request: %w", err)
 		}
 		req.X509Certificate.Raw = cert.Raw // adding the full certificate DER bytes
-
-		// TODO(hs): more properties required?
 		req.SCEPTransactionID = transactionID
 		resp, err := wh.DoWithContext(ctx, c.client, req, nil)
 		if err != nil {
@@ -211,14 +209,15 @@ func (c *notificationController) Success(ctx context.Context, csr *x509.Certific
 	return nil
 }
 
-func (c *notificationController) Failure(ctx context.Context, csr *x509.CertificateRequest, transactionID string) error {
+func (c *notificationController) Failure(ctx context.Context, csr *x509.CertificateRequest, transactionID string, errorCode int, errorDescription string) error {
 	for _, wh := range c.webhooks {
 		req, err := webhook.NewRequestBody(webhook.WithX509CertificateRequest(csr))
 		if err != nil {
 			return fmt.Errorf("failed creating new webhook request: %w", err)
 		}
-		// TODO(hs): more properties, such as error message / code required?
 		req.SCEPTransactionID = transactionID
+		req.SCEPErrorCode = errorCode
+		req.SCEPErrorDescription = errorDescription
 		resp, err := wh.DoWithContext(ctx, c.client, req, nil)
 		if err != nil {
 			return fmt.Errorf("failed executing webhook request: %w", err)
@@ -427,11 +426,11 @@ func (s *SCEP) NotifySuccess(ctx context.Context, csr *x509.CertificateRequest,
 	return s.notificationController.Success(ctx, csr, cert, transactionID)
 }
 
-func (s *SCEP) NotifyFailure(ctx context.Context, csr *x509.CertificateRequest, transactionID string) error {
+func (s *SCEP) NotifyFailure(ctx context.Context, csr *x509.CertificateRequest, transactionID string, errorCode int, errorDescription string) error {
 	if s.notificationController == nil {
 		return fmt.Errorf("provisioner %q wasn't initialized", s.Name)
 	}
-	return s.notificationController.Failure(ctx, csr, transactionID)
+	return s.notificationController.Failure(ctx, csr, transactionID, errorCode, errorDescription)
 }
 
 type validationMethod string
diff --git a/scep/api/api.go b/scep/api/api.go
index f7beb7a1..74259a8e 100644
--- a/scep/api/api.go
+++ b/scep/api/api.go
@@ -333,6 +333,9 @@ func PKIOperation(ctx context.Context, req request) (Response, error) {
 
 	certRep, err := auth.SignCSR(ctx, csr, msg)
 	if err != nil {
+		// default to ERROR_INTERNAL_ERROR: https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-erref/18d8fbe8-a967-4f1c-ae50-99ca8e491d2d
+		errorCode := 0x0000054F
+		errorDescription := err.Error()
 		if notifyErr := auth.NotifyFailure(ctx, csr, transactionID); notifyErr != nil {
 			// TODO(hs): ignore this error case? It's not critical if the notification fails; but logging it might be good
 			_ = notifyErr
diff --git a/scep/authority.go b/scep/authority.go
index 027d11fe..292c7004 100644
--- a/scep/authority.go
+++ b/scep/authority.go
@@ -513,9 +513,9 @@ func (a *Authority) NotifySuccess(ctx context.Context, csr *x509.CertificateRequ
 	return p.NotifySuccess(ctx, csr, cert, transactionID)
 }
 
-func (a *Authority) NotifyFailure(ctx context.Context, csr *x509.CertificateRequest, transactionID string) error {
+func (a *Authority) NotifyFailure(ctx context.Context, csr *x509.CertificateRequest, transactionID string, errorCode int, errorDescription string) error {
 	p := provisionerFromContext(ctx)
-	return p.NotifyFailure(ctx, csr, transactionID)
+	return p.NotifyFailure(ctx, csr, transactionID, errorCode, errorDescription)
 }
 
 func (a *Authority) selectDecrypter(ctx context.Context) (cert *x509.Certificate, decrypter crypto.Decrypter, err error) {
diff --git a/scep/provisioner.go b/scep/provisioner.go
index cb894c05..3df4b367 100644
--- a/scep/provisioner.go
+++ b/scep/provisioner.go
@@ -22,7 +22,7 @@ type Provisioner interface {
 	GetContentEncryptionAlgorithm() int
 	ValidateChallenge(ctx context.Context, csr *x509.CertificateRequest, challenge, transactionID string) error
 	NotifySuccess(ctx context.Context, csr *x509.CertificateRequest, cert *x509.Certificate, transactionID string) error
-	NotifyFailure(ctx context.Context, csr *x509.CertificateRequest, transactionID string) error
+	NotifyFailure(ctx context.Context, csr *x509.CertificateRequest, transactionID string, errorCode int, errorDescription string) error
 }
 
 // provisionerKey is the key type for storing and searching a
diff --git a/webhook/types.go b/webhook/types.go
index 330250f5..4c443969 100644
--- a/webhook/types.go
+++ b/webhook/types.go
@@ -81,8 +81,10 @@ type RequestBody struct {
 	SSHCertificateRequest  *SSHCertificateRequest  `json:"sshCertificateRequest,omitempty"`
 	SSHCertificate         *SSHCertificate         `json:"sshCertificate,omitempty"`
 	// Only set for SCEP challenge validation requests
-	SCEPChallenge     string `json:"scepChallenge,omitempty"`
-	SCEPTransactionID string `json:"scepTransactionID,omitempty"`
+	SCEPChallenge        string `json:"scepChallenge,omitempty"`
+	SCEPTransactionID    string `json:"scepTransactionID,omitempty"`
+	SCEPErrorCode        int    `json:"scepErrorCode,omitempty"`
+	SCEPErrorDescription string `json:"scepErrorDescription,omitempty"`
 	// Only set for X5C provisioners
 	X5CCertificate *X5CCertificate `json:"x5cCertificate,omitempty"`
 	// Set for X5C, AWS, GCP, and Azure provisioners