diff --git a/core/api/system-current.txt b/core/api/system-current.txt
index 125002dc9c78a..242c7375b1fd7 100644
--- a/core/api/system-current.txt
+++ b/core/api/system-current.txt
@@ -11880,6 +11880,7 @@ package android.telephony.ims {
     ctor public SipMessage(@NonNull String, @NonNull String, @NonNull byte[]);
     method public int describeContents();
     method @NonNull public byte[] getContent();
+    method @NonNull public byte[] getEncodedMessage();
     method @NonNull public String getHeaderSection();
     method @NonNull public String getStartLine();
     method public void writeToParcel(@NonNull android.os.Parcel, int);
diff --git a/telephony/java/android/telephony/ims/SipMessage.java b/telephony/java/android/telephony/ims/SipMessage.java
index 006cca84e44ba..9cfa640fce18c 100644
--- a/telephony/java/android/telephony/ims/SipMessage.java
+++ b/telephony/java/android/telephony/ims/SipMessage.java
@@ -16,6 +16,8 @@
 
 package android.telephony.ims;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+
 import android.annotation.NonNull;
 import android.annotation.SystemApi;
 import android.os.Build;
@@ -39,6 +41,7 @@ import java.util.Objects;
 public final class SipMessage implements Parcelable {
     // Should not be set to true for production!
     private static final boolean IS_DEBUGGING = Build.IS_ENG;
+    private static final String CRLF = "\r\n";
 
     private final String mStartLine;
     private final String mHeaderSection;
@@ -165,4 +168,19 @@ public final class SipMessage implements Parcelable {
         result = 31 * result + Arrays.hashCode(mContent);
         return result;
     }
+
+    /**
+     * @return the UTF-8 encoded SIP message.
+     */
+    public @NonNull byte[] getEncodedMessage() {
+        byte[] header = new StringBuilder()
+                .append(mStartLine)
+                .append(mHeaderSection)
+                .append(CRLF)
+                .toString().getBytes(UTF_8);
+        byte[] sipMessage = new byte[header.length + mContent.length];
+        System.arraycopy(header, 0, sipMessage, 0, header.length);
+        System.arraycopy(mContent, 0, sipMessage, header.length, mContent.length);
+        return sipMessage;
+    }
 }