diff --git a/infra/enrolment-records/repository/src/main/java/com/simprints/infra/enrolment/records/repository/remote/models/face/ApiFaceReference.kt b/infra/enrolment-records/repository/src/main/java/com/simprints/infra/enrolment/records/repository/remote/models/face/ApiFaceReference.kt
index 6eb6e5f811..41d0ac2807 100644
--- a/infra/enrolment-records/repository/src/main/java/com/simprints/infra/enrolment/records/repository/remote/models/face/ApiFaceReference.kt
+++ b/infra/enrolment-records/repository/src/main/java/com/simprints/infra/enrolment/records/repository/remote/models/face/ApiFaceReference.kt
@@ -1,15 +1,22 @@
 package com.simprints.infra.enrolment.records.repository.remote.models.face
 
 import androidx.annotation.Keep
+import com.fasterxml.jackson.annotation.JsonTypeInfo
+import com.simprints.core.ExcludedFromGeneratedTestCoverageReports
 import com.simprints.core.domain.face.FaceSample
 import com.simprints.core.tools.utils.EncodingUtils
 import com.simprints.infra.enrolment.records.repository.remote.models.ApiBiometricReference
 
 @Keep
+@ExcludedFromGeneratedTestCoverageReports("API model")
 internal data class ApiFaceReference(
     val id: String,
     val templates: List<ApiFaceTemplate>,
     val format: String,
+    // [MS-1076] The parent 'ApiBiometricReference' class should have its JsonSubTypes annotation updated to
+    // @JsonSubTypes.Type([...], looseHandling = true) once we update to SDK => 25 and Jackson => 2.16.0.
+    // Then, this annotation should be removed
+    @JsonTypeInfo(use = JsonTypeInfo.Id.NONE)
     val metadata: HashMap<String, String>? = null,
 ) : ApiBiometricReference(ApiBiometricReferenceType.FaceReference)
 
diff --git a/infra/enrolment-records/repository/src/main/java/com/simprints/infra/enrolment/records/repository/remote/models/fingerprint/ApiFingerprintReference.kt b/infra/enrolment-records/repository/src/main/java/com/simprints/infra/enrolment/records/repository/remote/models/fingerprint/ApiFingerprintReference.kt
index 434f1d9be3..f301bffe29 100644
--- a/infra/enrolment-records/repository/src/main/java/com/simprints/infra/enrolment/records/repository/remote/models/fingerprint/ApiFingerprintReference.kt
+++ b/infra/enrolment-records/repository/src/main/java/com/simprints/infra/enrolment/records/repository/remote/models/fingerprint/ApiFingerprintReference.kt
@@ -1,15 +1,22 @@
 package com.simprints.infra.enrolment.records.repository.remote.models.fingerprint
 
 import androidx.annotation.Keep
+import com.fasterxml.jackson.annotation.JsonTypeInfo
+import com.simprints.core.ExcludedFromGeneratedTestCoverageReports
 import com.simprints.core.domain.fingerprint.FingerprintSample
 import com.simprints.core.tools.utils.EncodingUtils
 import com.simprints.infra.enrolment.records.repository.remote.models.ApiBiometricReference
 
 @Keep
+@ExcludedFromGeneratedTestCoverageReports("API model")
 internal data class ApiFingerprintReference(
     val id: String,
     val templates: List<ApiFingerprintTemplate>,
     val format: String,
+    // [MS-1076] The parent 'ApiBiometricReference' class should have its JsonSubTypes annotation updated to
+    // @JsonSubTypes.Type([...], looseHandling = true) once we update to SDK => 25 and Jackson => 2.16.0.
+    // Then, this annotation should be removed
+    @JsonTypeInfo(use = JsonTypeInfo.Id.NONE)
     val metadata: HashMap<String, String>? = null,
 ) : ApiBiometricReference(ApiBiometricReferenceType.FingerprintReference)
 
diff --git a/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/ApiBiometricReference.kt b/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/ApiBiometricReference.kt
index be36c02770..46e5ba36a6 100644
--- a/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/ApiBiometricReference.kt
+++ b/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/ApiBiometricReference.kt
@@ -3,6 +3,7 @@ package com.simprints.infra.eventsync.event.remote.models.subject.biometricref
 import androidx.annotation.Keep
 import com.fasterxml.jackson.annotation.JsonSubTypes
 import com.fasterxml.jackson.annotation.JsonTypeInfo
+import com.simprints.core.ExcludedFromGeneratedTestCoverageReports
 import com.simprints.core.domain.fingerprint.IFingerIdentifier
 import com.simprints.infra.events.event.domain.models.subject.FaceTemplate
 import com.simprints.infra.events.event.domain.models.subject.FingerprintTemplate
@@ -16,8 +17,12 @@ import com.simprints.infra.events.event.domain.models.subject.FingerprintReferen
 private const val FACE_REFERENCE_KEY = "FaceReference"
 private const val FINGERPRINT_REFERENCE_KEY = "FingerprintReference"
 
+@ExcludedFromGeneratedTestCoverageReports("API model")
 @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.EXISTING_PROPERTY, property = "type", visible = true)
 @JsonSubTypes(
+    // [MS-1076] Annotations should have 'looseHandling' parameter passed to it to allow loose type handling of the nested fields (metadata)
+    // @JsonSubTypes.Type([...], looseHandling = true) once we update to SDK => 25 and Jackson => 2.16.0.
+    // Ref: https://github.com/FasterXML/jackson-databind/issues/3877#issuecomment-1508508854
     JsonSubTypes.Type(value = ApiFaceReference::class, name = FACE_REFERENCE_KEY),
     JsonSubTypes.Type(value = ApiFingerprintReference::class, name = FINGERPRINT_REFERENCE_KEY),
 )
diff --git a/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/face/ApiFaceReference.kt b/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/face/ApiFaceReference.kt
index f932252a9e..7ffb71250e 100644
--- a/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/face/ApiFaceReference.kt
+++ b/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/face/ApiFaceReference.kt
@@ -1,17 +1,24 @@
 package com.simprints.infra.eventsync.event.remote.models.subject.biometricref.face
 
 import androidx.annotation.Keep
+import com.fasterxml.jackson.annotation.JsonTypeInfo
+import com.simprints.core.ExcludedFromGeneratedTestCoverageReports
 import com.simprints.infra.eventsync.event.remote.models.subject.biometricref.ApiBiometricReference
 import com.simprints.infra.eventsync.event.remote.models.subject.biometricref.ApiBiometricReferenceType
 import com.simprints.infra.eventsync.event.remote.models.subject.biometricref.ApiBiometricReferenceType.FaceReference
 import java.util.UUID
 
 @Keep
+@ExcludedFromGeneratedTestCoverageReports("API model")
 internal data class ApiFaceReference(
     override val id: String = UUID.randomUUID().toString(),
     val templates: List<ApiFaceTemplate>,
     val format: String,
-    val metadata: HashMap<String, String>? = null,
+    // [MS-1076] The parent 'ApiBiometricReference' class should have its JsonSubTypes annotation updated to
+    // @JsonSubTypes.Type([...], looseHandling = true) once we update to SDK => 25 and Jackson => 2.16.0.
+    // Then, this annotation should be removed
+    @JsonTypeInfo(use = JsonTypeInfo.Id.NONE)
+    val metadata: Map<String, String>? = null,
 ) : ApiBiometricReference {
     override val type: ApiBiometricReferenceType = FaceReference
 }
diff --git a/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/fingerprint/ApiFingerprintReference.kt b/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/fingerprint/ApiFingerprintReference.kt
index d439d03da3..58fb8243ac 100644
--- a/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/fingerprint/ApiFingerprintReference.kt
+++ b/infra/event-sync/src/main/java/com/simprints/infra/eventsync/event/remote/models/subject/biometricref/fingerprint/ApiFingerprintReference.kt
@@ -1,17 +1,24 @@
 package com.simprints.infra.eventsync.event.remote.models.subject.biometricref.fingerprint
 
 import androidx.annotation.Keep
+import com.fasterxml.jackson.annotation.JsonTypeInfo
+import com.simprints.core.ExcludedFromGeneratedTestCoverageReports
 import com.simprints.infra.eventsync.event.remote.models.subject.biometricref.ApiBiometricReference
 import com.simprints.infra.eventsync.event.remote.models.subject.biometricref.ApiBiometricReferenceType
 import com.simprints.infra.eventsync.event.remote.models.subject.biometricref.ApiBiometricReferenceType.FingerprintReference
 import java.util.UUID
 
 @Keep
+@ExcludedFromGeneratedTestCoverageReports("API model")
 internal data class ApiFingerprintReference(
     override val id: String = UUID.randomUUID().toString(),
     val templates: List<ApiFingerprintTemplate>,
     val format: String,
-    val metadata: HashMap<String, String>? = null,
+    // [MS-1076] The parent 'ApiBiometricReference' class should have its JsonSubTypes annotation updated to
+    // @JsonSubTypes.Type([...], looseHandling = true) once we update to SDK => 25 and Jackson => 2.16.0.
+    // Then, this annotation should be removed
+    @JsonTypeInfo(use = JsonTypeInfo.Id.NONE)
+    val metadata: Map<String, String>? = null,
 ) : ApiBiometricReference {
     override val type: ApiBiometricReferenceType = FingerprintReference
 }
diff --git a/infra/events/src/main/java/com/simprints/infra/events/event/domain/models/subject/BiometricReference.kt b/infra/events/src/main/java/com/simprints/infra/events/event/domain/models/subject/BiometricReference.kt
index fe5e6b0b09..c8eed959ce 100644
--- a/infra/events/src/main/java/com/simprints/infra/events/event/domain/models/subject/BiometricReference.kt
+++ b/infra/events/src/main/java/com/simprints/infra/events/event/domain/models/subject/BiometricReference.kt
@@ -3,9 +3,11 @@ package com.simprints.infra.events.event.domain.models.subject
 import androidx.annotation.Keep
 import com.fasterxml.jackson.annotation.JsonSubTypes
 import com.fasterxml.jackson.annotation.JsonTypeInfo
+import com.simprints.core.ExcludedFromGeneratedTestCoverageReports
 import com.simprints.infra.events.event.domain.models.subject.BiometricReferenceType.Companion.FACE_REFERENCE_KEY
 import com.simprints.infra.events.event.domain.models.subject.BiometricReferenceType.Companion.FINGERPRINT_REFERENCE_KEY
 
+@ExcludedFromGeneratedTestCoverageReports("Domain model")
 @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.EXISTING_PROPERTY, property = "type")
 @JsonSubTypes(
     JsonSubTypes.Type(value = FaceReference::class, name = FACE_REFERENCE_KEY),
@@ -17,18 +19,20 @@ sealed class BiometricReference(
     val type: BiometricReferenceType,
 )
 
+@ExcludedFromGeneratedTestCoverageReports("Domain model")
 data class FaceReference(
     override val id: String,
     val templates: List<FaceTemplate>,
     val format: String,
-    val metadata: HashMap<String, String>? = null,
+    val metadata: Map<String, String>? = null,
 ) : BiometricReference(id, BiometricReferenceType.FACE_REFERENCE)
 
+@ExcludedFromGeneratedTestCoverageReports("Domain model")
 data class FingerprintReference(
     override val id: String,
     val templates: List<FingerprintTemplate>,
     val format: String,
-    val metadata: HashMap<String, String>? = null,
+    val metadata: Map<String, String>? = null,
 ) : BiometricReference(id, BiometricReferenceType.FINGERPRINT_REFERENCE)
 
 enum class BiometricReferenceType {