diff --git a/Feature.Manager.Api/FeatureRuns/Exceptions/FeatureRunAlreadyStoppedException.cs b/Feature.Manager.Api/FeatureRuns/Exceptions/FeatureRunAlreadyStoppedException.cs
new file mode 100644
index 0000000..b6bccbe
--- /dev/null
+++ b/Feature.Manager.Api/FeatureRuns/Exceptions/FeatureRunAlreadyStoppedException.cs
@@ -0,0 +1,9 @@
+using System;
+
+namespace Feature.Manager.Api.FeatureRuns.Exceptions
+{
+    public class FeatureRunAlreadyStoppedException : Exception
+    {
+        
+    }
+}
diff --git a/Feature.Manager.Api/FeatureRuns/FeatureRunService.cs b/Feature.Manager.Api/FeatureRuns/FeatureRunService.cs
index 674ff20..1b05910 100644
--- a/Feature.Manager.Api/FeatureRuns/FeatureRunService.cs
+++ b/Feature.Manager.Api/FeatureRuns/FeatureRunService.cs
@@ -34,7 +34,7 @@ public async Task<FeatureRun> CreateFeatureRun(CreateFeatureRunRequest request)
             try
             {
                 var runs = await _featureRunRepository.GetRunsForFeatureByFeatId(request.FeatId);
-                if (runs.Any(x => x.EndAt == null))
+                if (runs.Any(x => x.EndAt == null || x.StopResult == StopResult.AllB))
                 {
                     throw new FeatureAlreadyRunningException();
                 }
@@ -82,6 +82,11 @@ public async Task<FeatureRun> StopFeatureRun(StopFeatureRunRequest request)
                     throw new FeatureRunNotFoundException();
                 }
 
+                if (result.EndAt?.ToUniversalTime() <= DateTime.UtcNow && result.StopResult != StopResult.AllB)
+                {
+                    throw new FeatureRunAlreadyStoppedException();
+                }
+
                 if (!Enum.TryParse(request.StopResult, out StopResult stopResult))
                 {
                     throw new InvalidStopResultValueException();
@@ -89,6 +94,10 @@ public async Task<FeatureRun> StopFeatureRun(StopFeatureRunRequest request)
 
                 return await _featureRunRepository.StopFeatureRun(request);
             }
+            catch (FeatureRunAlreadyStoppedException)
+            {
+                throw;
+            }
             catch (FeatureRunNotFoundException)
             {
                 throw;
diff --git a/Feature.Manager.Api/FeatureRuns/FeatureRunsController.cs b/Feature.Manager.Api/FeatureRuns/FeatureRunsController.cs
index 0abd414..8da5e0a 100644
--- a/Feature.Manager.Api/FeatureRuns/FeatureRunsController.cs
+++ b/Feature.Manager.Api/FeatureRuns/FeatureRunsController.cs
@@ -119,6 +119,13 @@ public async Task<IActionResult> StopRun(StopFeatureRunRequest request)
                 var result = await _featureRunService.StopFeatureRun(request);
                 return Ok(result);
             }
+            catch (FeatureRunAlreadyStoppedException)
+            {
+                return BadRequest(new ProblemDetails
+                {
+                    Title = "Run Already stopped"
+                });
+            }
             catch (InvalidStopResultValueException)
             {
                 return BadRequest(new ProblemDetails
diff --git a/Feature.Manager.UnitTest/FeatureRuns/FeatureRunCreateServiceTest.cs b/Feature.Manager.UnitTest/FeatureRuns/FeatureRunCreateServiceTest.cs
index b205eb3..cae5492 100644
--- a/Feature.Manager.UnitTest/FeatureRuns/FeatureRunCreateServiceTest.cs
+++ b/Feature.Manager.UnitTest/FeatureRuns/FeatureRunCreateServiceTest.cs
@@ -75,6 +75,10 @@ public void Setup()
             {
                 MakeFeatureRun(StopResult.AllB, "APP-5", DateTime.Now.Subtract(TimeSpan.FromHours(12)))
             });
+            mock.Setup(x => x.GetRunsForFeatureByFeatId("APP-6")).ReturnsAsync(new List<FeatureRun>
+            {
+                MakeFeatureRun(StopResult.AllA, "APP-6", DateTime.Now.Subtract(TimeSpan.FromHours(12)))
+            });
             mock.Setup(x => x.GetRunsForFeatureByFeatId("APP-19")).ReturnsAsync(new List<FeatureRun>());
             _mock = mock;
             var featureRepository = new Mock<IFeatureRepository>();
@@ -116,19 +120,35 @@ public async Task TestCannotCreateNewRunIfARunIsAlreadyRunning()
                     StartAt = DateTime.Now,
                     FeatId = "APP-2"
                 }));
+            Assert.ThrowsAsync<FeatureAlreadyRunningException>(() => _featureRunService.CreateFeatureRun(
+                new CreateFeatureRunRequest
+                {
+                    Allocation = 100,
+                    EndAt = DateTime.Now.Add(TimeSpan.FromDays(20)),
+                    StartAt = DateTime.Now,
+                    FeatId = "APP-5"
+                }));
         }
 
         [Test]
         public async Task TestCreatesNewRunWhenNoFeaturesAreRunning()
         {
-            var result = await _featureRunService.CreateFeatureRun(new CreateFeatureRunRequest
+            var app3 = await _featureRunService.CreateFeatureRun(new CreateFeatureRunRequest
             {
                 Allocation = 100,
                 EndAt = DateTime.Now.Add(TimeSpan.FromDays(20)),
                 StartAt = DateTime.Now,
                 FeatId = "APP-3"
             });
-            Assert.NotNull(result);
+            var app6 = await _featureRunService.CreateFeatureRun(new CreateFeatureRunRequest
+            {
+                Allocation = 100,
+                EndAt = DateTime.Now.Add(TimeSpan.FromDays(20)),
+                StartAt = DateTime.Now,
+                FeatId = "APP-6"
+            });
+            Assert.NotNull(app3);
+            Assert.NotNull(app6);
         }
 
         [Test]
diff --git a/Feature.Manager.UnitTest/FeatureRuns/FeatureRunServiceTest.cs b/Feature.Manager.UnitTest/FeatureRuns/FeatureRunServiceTest.cs
index 7833665..ef75514 100644
--- a/Feature.Manager.UnitTest/FeatureRuns/FeatureRunServiceTest.cs
+++ b/Feature.Manager.UnitTest/FeatureRuns/FeatureRunServiceTest.cs
@@ -38,6 +38,46 @@ public void Setup()
                 FeatId = "APP-1",
                 RunToken = "RAND-UUID-TOKEN",
             });
+            mock.Setup(x => x.GetById("stopped-run-all-b")).ReturnsAsync(new FeatureRun
+            {
+                Allocation = 100,
+                Id = "stopped-run-all-b",
+                EndAt = DateTime.Now.Subtract(TimeSpan.FromSeconds(5)),
+                StartAt = DateTime.Now.Subtract(TimeSpan.FromDays(2)),
+                StopResult = StopResult.AllB,
+                FeatId = "APP-1",
+                RunToken = "RAND-UUID-TOKEN",
+            });
+            mock.Setup(x => x.GetById("stopped-run-changed-settings")).ReturnsAsync(new FeatureRun
+            {
+                Allocation = 100,
+                Id = "stopped-run-changed-settings",
+                EndAt = DateTime.Now.Subtract(TimeSpan.FromSeconds(5)),
+                StartAt = DateTime.Now.Subtract(TimeSpan.FromDays(2)),
+                StopResult = StopResult.ChangeSettings,
+                FeatId = "APP-1",
+                RunToken = "RAND-UUID-TOKEN",
+            });
+            mock.Setup(x => x.GetById("stopped-run-all-a")).ReturnsAsync(new FeatureRun
+            {
+                Allocation = 100,
+                Id = "stopped-run-all-a",
+                EndAt = DateTime.Now.Subtract(TimeSpan.FromSeconds(5)),
+                StopResult = StopResult.AllA,
+                StartAt = DateTime.Now.Subtract(TimeSpan.FromDays(2)),
+                FeatId = "APP-1",
+                RunToken = "RAND-UUID-TOKEN",
+            });
+            mock.Setup(x => x.GetById("stopped-run-removed-from-code")).ReturnsAsync(new FeatureRun
+            {
+                Allocation = 100,
+                Id = "stopped-run-removed-from-code",
+                EndAt = DateTime.Now.Subtract(TimeSpan.FromSeconds(5)),
+                StopResult = StopResult.Removed,
+                StartAt = DateTime.Now.Subtract(TimeSpan.FromDays(2)),
+                FeatId = "APP-1",
+                RunToken = "RAND-UUID-TOKEN",
+            });
             mock.Setup(x => x.GetById("RUN-UUID-3")).ThrowsAsync(new InvalidCastException());
             mock.Setup(x => x.StopFeatureRun(It.IsAny<StopFeatureRunRequest>())).ReturnsAsync(
                 (StopFeatureRunRequest request) =>
@@ -199,5 +239,35 @@ public async Task TestGetRunningFeaturesHandlesException()
             var systemUnderTest = new FeatureRunService(mock.Object, null);
             Assert.ThrowsAsync<UnknownDbException>(() => systemUnderTest.GetRunningFeatures());
         }
+
+        [Test]
+        public async Task StoppedRunsCantBeStoppedFurther()
+        {
+            Assert.ThrowsAsync<FeatureRunAlreadyStoppedException>(() => _featureRunService.StopFeatureRun(new StopFeatureRunRequest
+            {
+                RunId = "stopped-run-changed-settings",
+                StopResult = "AllB"
+            }));
+            Assert.ThrowsAsync<FeatureRunAlreadyStoppedException>(() => _featureRunService.StopFeatureRun(new StopFeatureRunRequest
+            {
+                RunId = "stopped-run-all-a",
+                StopResult = "AllB"
+            }));
+            Assert.ThrowsAsync<FeatureRunAlreadyStoppedException>(() => _featureRunService.StopFeatureRun(new StopFeatureRunRequest
+            {
+                RunId = "stopped-run-removed-from-code",
+                StopResult = "AllB"
+            }));
+        }
+
+        [Test]
+        public async Task StoppedAllBRunsCanBeChanged()
+        {
+            Assert.DoesNotThrowAsync(() => _featureRunService.StopFeatureRun(new StopFeatureRunRequest
+            {
+                RunId = "stopped-run-all-b",
+                StopResult = "AllA"
+            }));
+        }
     }
 }