diff --git a/src/AR.Iec61850/Scl/Export/AuthoritativeLiveIedSclExporter.cs b/src/AR.Iec61850/Scl/Export/AuthoritativeLiveIedSclExporter.cs
new file mode 100644
index 0000000..499a99a
--- /dev/null
+++ b/src/AR.Iec61850/Scl/Export/AuthoritativeLiveIedSclExporter.cs
@@ -0,0 +1,156 @@
+using System.Xml.Linq;
+using AR.Iec61850.Discovery;
+
+namespace AR.Iec61850.Scl.Export;
+
+/// <summary>
+/// Exports a live-discovery model while keeping the physical IED identity separate from
+/// communication-level MMS Logical Device domain names.
+/// </summary>
+public static class AuthoritativeLiveIedSclExporter
+{
+    private static readonly XNamespace Scl = "http://www.iec.ch/61850/2003/SCL";
+
+    public static LiveIedSclExportResult WriteFiles(
+        LiveIedModelDiscoveryDocument model,
+        string sclPath,
+        LiveIedSclExportOptions? options = null)
+    {
+        ArgumentNullException.ThrowIfNull(model);
+        options ??= new LiveIedSclExportOptions();
+
+        var result = LiveIedSclExporter.WriteFiles(model, sclPath, options);
+        if (string.IsNullOrWhiteSpace(options.IedNameOverride))
+            return result;
+
+        var document = XDocument.Load(result.SclPath, LoadOptions.PreserveWhitespace);
+        ApplyIdentity(document, model, options.IedNameOverride);
+        document.Save(result.SclPath);
+        return result;
+    }
+
+    public static XDocument ApplyIdentity(
+        XDocument source,
+        LiveIedModelDiscoveryDocument model,
+        string authoritativeIedName)
+    {
+        ArgumentNullException.ThrowIfNull(source);
+        ArgumentNullException.ThrowIfNull(model);
+        if (string.IsNullOrWhiteSpace(authoritativeIedName))
+            throw new ArgumentException("Authoritative IED name is empty.", nameof(authoritativeIedName));
+
+        var document = new XDocument(source);
+        var root = document.Root ?? throw new InvalidDataException("Generated SCL document has no root element.");
+        var safeIedName = SafeXmlName(authoritativeIedName);
+
+        var ied = root.Elements(Scl + "IED").SingleOrDefault()
+            ?? throw new InvalidDataException("Generated live SCL must contain exactly one IED element.");
+        ied.SetAttributeValue("name", safeIedName);
+
+        foreach (var connectedAp in root.Descendants(Scl + "ConnectedAP"))
+            connectedAp.SetAttributeValue("iedName", safeIedName);
+
+        var header = root.Element(Scl + "Header");
+        header?.SetAttributeValue("id", $"{safeIedName}_GENERATED");
+
+        var logicalDevices = ied.Descendants(Scl + "LDevice").ToArray();
+        var unmatchedDomains = new HashSet<string>(
+            model.LogicalDevices
+                .Select(LogicalDeviceDomain)
+                .Where(domain => !string.IsNullOrWhiteSpace(domain)),
+            StringComparer.OrdinalIgnoreCase);
+
+        foreach (var logicalDevice in logicalDevices)
+        {
+            var inst = ((string?)logicalDevice.Attribute("inst") ?? string.Empty).Trim();
+            if (string.IsNullOrWhiteSpace(inst))
+                continue;
+
+            var domain = MatchMmsDomain(inst, model.IedName, unmatchedDomains);
+            if (string.IsNullOrWhiteSpace(domain))
+                continue;
+
+            unmatchedDomains.Remove(domain);
+            var implicitName = $"{safeIedName}{inst}";
+            logicalDevice.SetAttributeValue(
+                "ldName",
+                domain.Equals(implicitName, StringComparison.OrdinalIgnoreCase) ? null : domain);
+        }
+
+        ValidateIdentity(document, safeIedName, model);
+        return document;
+    }
+
+    private static string MatchMmsDomain(
+        string generatedInst,
+        string previousIedName,
+        IReadOnlySet<string> domains)
+    {
+        var direct = domains.FirstOrDefault(domain =>
+            domain.Equals(generatedInst, StringComparison.OrdinalIgnoreCase));
+        if (!string.IsNullOrWhiteSpace(direct))
+            return direct;
+
+        var previousImplicit = $"{previousIedName?.Trim()}{generatedInst}";
+        var implicitMatch = domains.FirstOrDefault(domain =>
+            domain.Equals(previousImplicit, StringComparison.OrdinalIgnoreCase));
+        if (!string.IsNullOrWhiteSpace(implicitMatch))
+            return implicitMatch;
+
+        return string.Empty;
+    }
+
+    private static void ValidateIdentity(
+        XDocument document,
+        string authoritativeIedName,
+        LiveIedModelDiscoveryDocument model)
+    {
+        var root = document.Root ?? throw new InvalidDataException("Normalized SCL has no root element.");
+        var ied = root.Elements(Scl + "IED").Single();
+        if (!authoritativeIedName.Equals((string?)ied.Attribute("name"), StringComparison.Ordinal))
+            throw new InvalidDataException("Normalized SCL IED identity does not match the authoritative IED name.");
+
+        if (root.Descendants(Scl + "ConnectedAP").Any(ap =>
+                !authoritativeIedName.Equals((string?)ap.Attribute("iedName"), StringComparison.Ordinal)))
+        {
+            throw new InvalidDataException("ConnectedAP identity is inconsistent with the normalized IED name.");
+        }
+
+        var exportedCommunicationNames = root.Descendants(Scl + "LDevice")
+            .Select(ld =>
+            {
+                var explicitName = ((string?)ld.Attribute("ldName") ?? string.Empty).Trim();
+                var inst = ((string?)ld.Attribute("inst") ?? string.Empty).Trim();
+                return string.IsNullOrWhiteSpace(explicitName)
+                    ? $"{authoritativeIedName}{inst}"
+                    : explicitName;
+            })
+            .ToHashSet(StringComparer.OrdinalIgnoreCase);
+
+        var missingDomains = model.LogicalDevices
+            .Select(LogicalDeviceDomain)
+            .Where(domain => !exportedCommunicationNames.Contains(domain))
+            .ToArray();
+        if (missingDomains.Length > 0)
+        {
+            throw new InvalidDataException(
+                $"Normalized SCL lost MMS Logical Device domain(s): {string.Join(", ", missingDomains)}.");
+        }
+    }
+
+    private static string LogicalDeviceDomain(LiveIedLogicalDeviceModel logicalDevice)
+        => string.IsNullOrWhiteSpace(logicalDevice.MmsDomain)
+            ? logicalDevice.Inst.Trim()
+            : logicalDevice.MmsDomain.Trim();
+
+    private static string SafeXmlName(string value)
+    {
+        var chars = value.Trim()
+            .Select(character => char.IsLetterOrDigit(character) || character is '_' or '-' ? character : '_')
+            .ToArray();
+        var result = new string(chars);
+        if (string.IsNullOrWhiteSpace(result))
+            return "LIVE_IED";
+        return char.IsLetter(result[0]) || result[0] == '_' ? result : $"_{result}";
+    }
+}
diff --git a/src/AR.Iec61850/Scl/Export/LiveIedSclExportModels.cs b/src/AR.Iec61850/Scl/Export/LiveIedSclExportModels.cs
index 3a233df..69dff6a 100644
--- a/src/AR.Iec61850/Scl/Export/LiveIedSclExportModels.cs
+++ b/src/AR.Iec61850/Scl/Export/LiveIedSclExportModels.cs
@@ -9,6 +9,12 @@ public sealed class LiveIedSclExportOptions
     public SclSchemaProfile SchemaProfile { get; init; } = SclSchemaProfile.Edition2V31;
     public string SubNetworkName { get; init; } = "StationBus";
     public string IpAddress { get; init; } = string.Empty;
+    /// <summary>
+    /// Authoritative SCL IED identity supplied by the caller. MMS exposes Logical Device
+    /// domain names, which are not a reliable source for recovering the enclosing IED name
+    /// when an implementation uses explicit communication-level LD names.
+    /// </summary>
+    public string IedNameOverride { get; init; } = string.Empty;
     public string IpSubnet { get; init; } = "255.255.255.0";
     public string IpGateway { get; init; } = "0.0.0.0";
     public string OsiApTitle { get; init; } = string.Empty;
diff --git a/tests/AR.Iec61850.Tests/Scl/LiveIedSclIedIdentityTests.cs b/tests/AR.Iec61850.Tests/Scl/LiveIedSclIedIdentityTests.cs
new file mode 100644
index 0000000..a89c62f
--- /dev/null
+++ b/tests/AR.Iec61850.Tests/Scl/LiveIedSclIedIdentityTests.cs
@@ -0,0 +1,134 @@
+using AR.Iec61850.Discovery;
+using AR.Iec61850.Scl.Export;
+using System.Xml.Linq;
+
+namespace AR.Iec61850.Tests.Scl;
+
+public sealed class LiveIedSclIedIdentityTests
+{
+    [Fact]
+    public void Exporter_Uses_Authoritative_Ied_Name_And_Preserves_Explicit_Mms_Domains()
+    {
+        var model = new LiveIedModelDiscoveryDocument
+        {
+            Host = "1.110.1.1",
+            // Reproduces the unsafe legacy heuristic: the first MMS domain was copied as IED name.
+            IedName = "OCR7SJ8Application",
+            AccessPointName = "AP1",
+            LogicalDevices =
+            [
+                LogicalDevice("OCR7SJ8Application"),
+                LogicalDevice("OCR7SJ8CB1")
+            ],
+            DataSets =
+            [
+                new LiveIedDataSetModel
+                {
+                    Reference = "OCR7SJ8Application/LLN0.DataSet",
+                    Domain = "OCR7SJ8Application",
+                    LogicalNode = "LLN0",
+                    Name = "DataSet",
+                    MemberCount = 1,
+                    Members =
+                    [
+                        new LiveIedDataSetMemberModel
+                        {
+                            Index = 0,
+                            Reference = "OCR7SJ8CB1/XCBR1.Pos.stVal",
+                            FunctionalConstraint = "ST"
+                        }
+                    ]
+                }
+            ],
+            ReportControls =
+            [
+                new LiveIedReportControlModel
+                {
+                    Reference = "OCR7SJ8Application/LLN0.RP.urcbD0101",
+                    Domain = "OCR7SJ8Application",
+                    LogicalNode = "LLN0",
+                    Name = "urcbD0101",
+                    Buffered = false,
+                    DataSetReference = "OCR7SJ8Application/LLN0.DataSet",
+                    ConfRev = "1"
+                }
+            ]
+        };
+
+        var generated = LiveIedSclExporter.BuildDocument(
+            model,
+            new LiveIedSclExportOptions
+            {
+                Profile = "full-model",
+                SchemaProfile = SclSchemaProfile.Edition1V16,
+                IpAddress = "1.110.1.1"
+            });
+        var document = AuthoritativeLiveIedSclExporter.ApplyIdentity(
+            generated,
+            model,
+            "OCR7SJ8Mod2");
+
+        var root = Assert.IsType<XElement>(document.Root);
+        var ns = root.Name.Namespace;
+        var ied = Assert.Single(root.Elements(ns + "IED"));
+        Assert.Equal("OCR7SJ8Mod2", (string?)ied.Attribute("name"));
+        Assert.Equal("OCR7SJ8Mod2", (string?)root.Descendants(ns + "ConnectedAP").Single().Attribute("iedName"));
+
+        var logicalDevices = root.Descendants(ns + "LDevice").ToArray();
+        Assert.Equal(2, logicalDevices.Length);
+        Assert.Contains(logicalDevices, ld =>
+            (string?)ld.Attribute("inst") == "OCR7SJ8Application" &&
+            (string?)ld.Attribute("ldName") == "OCR7SJ8Application");
+        Assert.Contains(logicalDevices, ld =>
+            (string?)ld.Attribute("inst") == "OCR7SJ8CB1" &&
+            (string?)ld.Attribute("ldName") == "OCR7SJ8CB1");
+
+        var report = Assert.Single(root.Descendants(ns + "ReportControl"));
+        Assert.Equal("urcbD0101", (string?)report.Attribute("name"));
+        var fcda = Assert.Single(root.Descendants(ns + "FCDA"));
+        Assert.Equal("OCR7SJ8CB1", (string?)fcda.Attribute("ldInst"));
+        Assert.DoesNotContain("OCR7SJ8Mod2OCR7SJ8Application", document.ToString(), StringComparison.Ordinal);
+    }
+
+    [Fact]
+    public void Exporter_Keeps_Implicit_Product_Naming_When_Domain_Starts_With_Ied_Name()
+    {
+        var model = new LiveIedModelDiscoveryDocument
+        {
+            IedName = "IED1",
+            LogicalDevices = [LogicalDevice("IED1PROT")]
+        };
+
+        var generated = LiveIedSclExporter.BuildDocument(model, new LiveIedSclExportOptions());
+        var document = AuthoritativeLiveIedSclExporter.ApplyIdentity(generated, model, "IED1");
+        var root = Assert.IsType<XElement>(document.Root);
+        var ns = root.Name.Namespace;
+        var logicalDevice = Assert.Single(root.Descendants(ns + "LDevice"));
+
+        Assert.Equal("PROT", (string?)logicalDevice.Attribute("inst"));
+        Assert.Null(logicalDevice.Attribute("ldName"));
+    }
+
+    private static LiveIedLogicalDeviceModel LogicalDevice(string domain)
+        => new()
+        {
+            MmsDomain = domain,
+            Inst = domain,
+            LogicalNodes =
+            [
+                new LiveIedLogicalNodeModel
+                {
+                    Name = "LLN0",
+                    LnClass = "LLN0",
+                    ProposedLnTypeId = $"LN_{domain}_LLN0"
+                },
+                new LiveIedLogicalNodeModel
+                {
+                    Name = "XCBR1",
+                    LnClass = "XCBR",
+                    LnInst = "1",
+                    ProposedLnTypeId = $"LN_{domain}_XCBR1"
+                }
+            ]
+        };
+}