diff --git a/autocodesign/devportalclient/appstoreconnectclient/profiles.go b/autocodesign/devportalclient/appstoreconnectclient/profiles.go
index 46ece7da..32683e04 100644
--- a/autocodesign/devportalclient/appstoreconnectclient/profiles.go
+++ b/autocodesign/devportalclient/appstoreconnectclient/profiles.go
@@ -399,6 +399,10 @@ func (c *ProfileClient) SyncBundleID(bundleID appstoreconnect.BundleID, appEntit
 		ent := autocodesign.Entitlement{key: value}
 		cap, err := ent.Capability()
 		if err != nil {
+			if errors.Is(err, autocodesign.ErrUnknownEntitlementKey) {
+				log.Warnf("Skipping unknown entitlement key %q while syncing bundle ID capabilities. If this is a recognised Apple entitlement that should be registered on App Store Connect, please report it to bitrise-io/go-xcode so it can be added to ServiceTypeByKey.", key)
+				continue
+			}
 			return err
 		}
 		if cap == nil {
diff --git a/autocodesign/entitlement.go b/autocodesign/entitlement.go
index cde18e67..78c0a54b 100644
--- a/autocodesign/entitlement.go
+++ b/autocodesign/entitlement.go
@@ -13,6 +13,14 @@ import (
 // ICloudIdentifiersEntitlementKey ...
 const ICloudIdentifiersEntitlementKey = "com.apple.developer.icloud-container-identifiers"
 
+// ErrUnknownEntitlementKey is returned by Entitlement.Capability and
+// Entitlement.Equal when an entitlement key is not present in
+// appstoreconnect.ServiceTypeByKey. Callers that iterate over a project's
+// full entitlement set (e.g. SyncBundleID) may wrap this with errors.Is to
+// skip unknown keys with a warning instead of aborting, so a single new
+// Apple-introduced key does not break the entire code signing flow.
+var ErrUnknownEntitlementKey = errors.New("unknown entitlement key")
+
 // DataProtections ...
 var DataProtections = map[string]appstoreconnect.CapabilityOptionKey{
 	"NSFileProtectionComplete":                             appstoreconnect.CompleteProtection,
@@ -44,7 +52,7 @@ func (e Entitlement) Capability() (*appstoreconnect.BundleIDCapability, error) {
 
 	capType, ok := appstoreconnect.ServiceTypeByKey[entKey]
 	if !ok {
-		return nil, errors.New("unknown entitlement key: " + entKey)
+		return nil, fmt.Errorf("%w: %s", ErrUnknownEntitlementKey, entKey)
 	}
 
 	if capType == appstoreconnect.Ignored {
@@ -144,7 +152,7 @@ func (e Entitlement) Equal(cap appstoreconnect.BundleIDCapability, allEntitlemen
 
 	capType, ok := appstoreconnect.ServiceTypeByKey[entKey]
 	if !ok {
-		return false, errors.New("unknown entitlement key: " + entKey)
+		return false, fmt.Errorf("%w: %s", ErrUnknownEntitlementKey, entKey)
 	}
 
 	if cap.Attributes.CapabilityType != capType {
diff --git a/autocodesign/entitlement_test.go b/autocodesign/entitlement_test.go
index 61ac5e9b..b90a6cb0 100644
--- a/autocodesign/entitlement_test.go
+++ b/autocodesign/entitlement_test.go
@@ -1,6 +1,7 @@
 package autocodesign
 
 import (
+	"errors"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -109,6 +110,18 @@ func TestCapability_HealthKitAccessIgnored(t *testing.T) {
 	require.Nil(t, cap)
 }
 
+func TestCapability_UnknownKeyReturnsSentinel(t *testing.T) {
+	ent := Entitlement(map[string]interface{}{
+		"com.apple.developer.totally-made-up-entitlement": true,
+	})
+
+	cap, err := ent.Capability()
+	require.Error(t, err)
+	require.True(t, errors.Is(err, ErrUnknownEntitlementKey))
+	require.Contains(t, err.Error(), "com.apple.developer.totally-made-up-entitlement")
+	require.Nil(t, cap)
+}
+
 func TestCapability_IgnoredKeys(t *testing.T) {
 	keys := []string{
 		"com.apple.developer.kernel.extended-virtual-addressing",