diff --git a/CHANGELOG.md b/CHANGELOG.md
index 33443a7..22f4af6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [1.6.0] - 2026-08-17
+
+### Added
+- **Template-controlled SMS sending** (CLOUD-2885): optional `TemplateId` on `SMSCampaign`/`SMSRequest`, plus new `SMS.SendWithTemplateAsync()` and `SMS.SendSingleWithTemplateAsync()` methods for accounts that require a pre-approved template.
+
 ## [1.4.0] - 2025-09-03
 
 ### Added
diff --git a/integration/Program.cs b/integration/Program.cs
index 20b38cd..81379f0 100644
--- a/integration/Program.cs
+++ b/integration/Program.cs
@@ -1,6 +1,7 @@
-// .NET SDK integration tests — 52 tests
+// .NET SDK integration tests — 54 tests
 // Covers: SMS (1-6), MMS (7-17), Email (18-22), Webhook (23-29), Contact (30-31),
-// Brands (32-36), Campaigns (37-42), ContactValidator (43-46), Negative cases (47-52)
+// Brands (32-36), Campaigns (37-42), ContactValidator (43-46), Negative cases (47-52),
+// SMS Templates (53-54)
 //
 // Test results use three states:
 //   PASS — the test ran and all assertions held
@@ -111,7 +112,7 @@ string WriteTempPng()
     "CCAI_TEST_FIRST_NAME", "CCAI_TEST_LAST_NAME",
     "CCAI_TEST_FIRST_NAME_2", "CCAI_TEST_LAST_NAME_2",
     "CCAI_TEST_FIRST_NAME_3", "CCAI_TEST_LAST_NAME_3",
-    "WEBHOOK_URL",
+    "WEBHOOK_URL", "CCAI_TEST_TEMPLATE_ID",
 ];
 var missing = requiredEnv.Where(k => string.IsNullOrEmpty(Environment.GetEnvironmentVariable(k))).ToList();
 if (missing.Count > 0)
@@ -134,6 +135,7 @@ string WriteTempPng()
 var ln2      = Environment.GetEnvironmentVariable("CCAI_TEST_LAST_NAME_2")!;
 var fn3      = Environment.GetEnvironmentVariable("CCAI_TEST_FIRST_NAME_3")!;
 var ln3      = Environment.GetEnvironmentVariable("CCAI_TEST_LAST_NAME_3")!;
+var templateId = long.Parse(Environment.GetEnvironmentVariable("CCAI_TEST_TEMPLATE_ID")!);
 
 // Unique per-run suffix so parallel SDK runs don't collide on the same webhook URL
 var runId = $"dotnet-{DateTimeOffset.UtcNow.ToUnixTimeSeconds()}";
@@ -823,6 +825,24 @@ await Run("52 PERMISSIVE: MMS.SendAsync with nonexistent fileKey (API accepts)",
             "nonexistent fileKey accepted", ".NET Permissive 52");
         AssertSmsResponse(resp);
     });
+
+    Console.WriteLine("\n--- SMS Templates ---");
+
+    await Run("53 SMS.SendWithTemplateAsync", async () =>
+    {
+        var resp = await client.SMS.SendWithTemplateAsync(
+            [
+                new Account { FirstName = fn1, LastName = ln1, Phone = phone1 },
+                new Account { FirstName = fn2, LastName = ln2, Phone = phone2 },
+            ], templateId, ".NET Template Test");
+        AssertSmsResponse(resp);
+    });
+
+    await Run("54 SMS.SendSingleWithTemplateAsync", async () =>
+    {
+        var resp = await client.SMS.SendSingleWithTemplateAsync(fn1, ln1, phone1, templateId, ".NET Single Template Test");
+        AssertSmsResponse(resp);
+    });
 }
 finally
 {
diff --git a/src/CCAI.NET/CCAI.NET.csproj b/src/CCAI.NET/CCAI.NET.csproj
index 1dc26a5..eeb84c8 100644
--- a/src/CCAI.NET/CCAI.NET.csproj
+++ b/src/CCAI.NET/CCAI.NET.csproj
@@ -6,7 +6,7 @@
     <Nullable>enable</Nullable>
     <LangVersion>latest</LangVersion>
     <PackageId>CloudContactAI.CCAI.NET</PackageId>
-    <Version>1.5.0</Version>
+    <Version>1.6.0</Version>
     <Authors>CloudContactAI LLC</Authors>
     <Company>CloudContactAI LLC</Company>
     <Description>C# client for CloudContactAI API with SMS, MMS, Email, and Webhook support. Enhanced webhook support with new CloudContact event format, contact.unsubscribed events, environment variable configuration, and comprehensive examples.</Description>
diff --git a/src/CCAI.NET/SMS/SMSService.cs b/src/CCAI.NET/SMS/SMSService.cs
index 43c98d0..210ae48 100644
--- a/src/CCAI.NET/SMS/SMSService.cs
+++ b/src/CCAI.NET/SMS/SMSService.cs
@@ -128,7 +128,7 @@ public async Task<SMSResponse> SendAsync(SMSRequest request, CancellationToken c
             throw new ArgumentException("At least one account is required", nameof(request.Accounts));
         }
         
-        if (string.IsNullOrEmpty(request.Message))
+        if (string.IsNullOrEmpty(request.Message) && request.TemplateId is null)
         {
             throw new ArgumentException("Message is required", nameof(request.Message));
         }