diff --git a/AccessGridTest/ConsoleServiceTests.cs b/AccessGridTest/ConsoleServiceTests.cs
index cd792e8..b729f2e 100644
--- a/AccessGridTest/ConsoleServiceTests.cs
+++ b/AccessGridTest/ConsoleServiceTests.cs
@@ -865,6 +865,21 @@ public async Task WebhooksDeleteAsync_ShouldDeleteWebhook()
         )), Times.Once);
     }
 
+    [Test]
+    public async Task WebhooksDeleteAsync_IncludesSigPayloadQueryParam()
+    {
+        // DELETE requests have no body, so the server looks for `sig_payload` in
+        // the query string and verifies the signature against that.
+        StubHttpResponse("{}");
+
+        await _client.Console.Webhooks.DeleteAsync("wh_123");
+
+        _mockHttpClient.Verify(x => x.SendAsync(It.Is<HttpRequestMessage>(req =>
+            req.Method == HttpMethod.Delete &&
+            req.RequestUri!.ToString().Contains("sig_payload=")
+        )), Times.Once);
+    }
+
     #endregion
 
     #region HIDOrgsService
diff --git a/src/AccessGrid/AccessGridClient.cs b/src/AccessGrid/AccessGridClient.cs
index 8c4923e..af34b10 100644
--- a/src/AccessGrid/AccessGridClient.cs
+++ b/src/AccessGrid/AccessGridClient.cs
@@ -163,7 +163,7 @@ private async Task<T> MakeRequestAsync<T>(HttpMethod method, string endpoint, ob
         {
             // Extract resource ID from the endpoint if needed for signature
             string resourceId = null;
-            if (method == HttpMethod.Get || (method == HttpMethod.Post && data == null))
+            if (method == HttpMethod.Get || method == HttpMethod.Delete || (method == HttpMethod.Post && data == null))
             {
                 // Extract the ID from the endpoint - patterns like /resource/{id} or /resource/{id}/action
                 var parts = endpoint.Trim('/').Split('/');
@@ -186,8 +186,9 @@ private async Task<T> MakeRequestAsync<T>(HttpMethod method, string endpoint, ob
             // Special handling for requests with no payload:
             // 1. POST requests with empty body (like unlink/suspend/resume)
             // 2. GET requests
+            // 3. DELETE requests (always have no body)
             string payload;
-            if ((method == HttpMethod.Post && data == null) || method == HttpMethod.Get)
+            if ((method == HttpMethod.Post && data == null) || method == HttpMethod.Get || method == HttpMethod.Delete)
             {
                 // For listing cards endpoint (like what the Python list.py script does)
                 if (method == HttpMethod.Get && endpoint == "/v1/key-cards")
@@ -228,7 +229,7 @@ private async Task<T> MakeRequestAsync<T>(HttpMethod method, string endpoint, ob
 
             // For GET requests or POST requests with empty bodies that need the sig_payload parameter
             // Note: We've already added sig_payload for /v1/key-cards endpoint above
-            if ((method == HttpMethod.Get || (method == HttpMethod.Post && data == null)) && !finalQueryParams.ContainsKey("sig_payload"))
+            if ((method == HttpMethod.Get || method == HttpMethod.Delete || (method == HttpMethod.Post && data == null)) && !finalQueryParams.ContainsKey("sig_payload"))
             {
                 if (!string.IsNullOrEmpty(resourceId) && resourceId != "key-cards" && !resourceId.Contains("templates"))
                 {
@@ -298,6 +299,12 @@ private async Task<T> MakeRequestAsync<T>(HttpMethod method, string endpoint, ob
                 return (T)(object)responseContent;
             }
 
+            // Empty response bodies (e.g. DELETE 204) have nothing to deserialize.
+            if (string.IsNullOrWhiteSpace(responseContent))
+            {
+                return default;
+            }
+
             // Deserialize the response
             try
             {