diff --git a/apps/dh/api-dh/source/DataHub.WebApi/Clients/Wholesale/V3/WholesaleClient.cs b/apps/dh/api-dh/source/DataHub.WebApi/Clients/Wholesale/V3/WholesaleClient.cs
index 1493379c94..5b037f8c95 100644
--- a/apps/dh/api-dh/source/DataHub.WebApi/Clients/Wholesale/V3/WholesaleClient.cs
+++ b/apps/dh/api-dh/source/DataHub.WebApi/Clients/Wholesale/V3/WholesaleClient.cs
@@ -50,7 +50,7 @@ public partial interface IWholesaleClient_V3
         /// </summary>
         /// <returns>OK</returns>
         /// <exception cref="ApiException">A server side error occurred.</exception>
-        System.Threading.Tasks.Task<System.Collections.Generic.ICollection<SettlementReportApplicableCalculationDto>> GetApplicableCalculationsAsync(CalculationType? calculationType = null, System.Collections.Generic.IEnumerable<string> gridAreaCodes = null, System.DateTimeOffset? periodStart = null, System.DateTimeOffset? periodEnd = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
+        System.Threading.Tasks.Task<System.Collections.Generic.ICollection<SettlementReportApplicableCalculationDto>> GetApplicableCalculationsAsync(CalculationType? calculationType = null, System.DateTimeOffset? periodStart = null, System.DateTimeOffset? periodEnd = null, System.Collections.Generic.IEnumerable<string> body = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken));
 
     }
 
@@ -283,7 +283,7 @@ public string BaseUrl
         /// </summary>
         /// <returns>OK</returns>
         /// <exception cref="ApiException">A server side error occurred.</exception>
-        public virtual async System.Threading.Tasks.Task<System.Collections.Generic.ICollection<SettlementReportApplicableCalculationDto>> GetApplicableCalculationsAsync(CalculationType? calculationType = null, System.Collections.Generic.IEnumerable<string> gridAreaCodes = null, System.DateTimeOffset? periodStart = null, System.DateTimeOffset? periodEnd = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
+        public virtual async System.Threading.Tasks.Task<System.Collections.Generic.ICollection<SettlementReportApplicableCalculationDto>> GetApplicableCalculationsAsync(CalculationType? calculationType = null, System.DateTimeOffset? periodStart = null, System.DateTimeOffset? periodEnd = null, System.Collections.Generic.IEnumerable<string> body = null, System.Threading.CancellationToken cancellationToken = default(System.Threading.CancellationToken))
         {
             var client_ = _httpClient;
             var disposeClient_ = false;
@@ -291,7 +291,11 @@ public string BaseUrl
             {
                 using (var request_ = new System.Net.Http.HttpRequestMessage())
                 {
-                    request_.Method = new System.Net.Http.HttpMethod("GET");
+                    var json_ = Newtonsoft.Json.JsonConvert.SerializeObject(body, _settings.Value);
+                    var content_ = new System.Net.Http.StringContent(json_);
+                    content_.Headers.ContentType = System.Net.Http.Headers.MediaTypeHeaderValue.Parse("application/json");
+                    request_.Content = content_;
+                    request_.Method = new System.Net.Http.HttpMethod("POST");
                     request_.Headers.Accept.Add(System.Net.Http.Headers.MediaTypeWithQualityHeaderValue.Parse("application/json"));
 
                     var urlBuilder_ = new System.Text.StringBuilder();
@@ -303,10 +307,6 @@ public string BaseUrl
                     {
                         urlBuilder_.Append(System.Uri.EscapeDataString("calculationType")).Append('=').Append(System.Uri.EscapeDataString(ConvertToString(calculationType, System.Globalization.CultureInfo.InvariantCulture))).Append('&');
                     }
-                    if (gridAreaCodes != null)
-                    {
-                        foreach (var item_ in gridAreaCodes) { urlBuilder_.Append(System.Uri.EscapeDataString("gridAreaCodes")).Append('=').Append(System.Uri.EscapeDataString(ConvertToString(item_, System.Globalization.CultureInfo.InvariantCulture))).Append('&'); }
-                    }
                     if (periodStart != null)
                     {
                         urlBuilder_.Append(System.Uri.EscapeDataString("periodStart")).Append('=').Append(System.Uri.EscapeDataString(periodStart.Value.ToString("s", System.Globalization.CultureInfo.InvariantCulture))).Append('&');
diff --git a/apps/dh/api-dh/source/DataHub.WebApi/Clients/Wholesale/V3/swagger.json b/apps/dh/api-dh/source/DataHub.WebApi/Clients/Wholesale/V3/swagger.json
index 6c552aa51c..fc051a0c80 100644
--- a/apps/dh/api-dh/source/DataHub.WebApi/Clients/Wholesale/V3/swagger.json
+++ b/apps/dh/api-dh/source/DataHub.WebApi/Clients/Wholesale/V3/swagger.json
@@ -124,7 +124,7 @@
       }
     },
     "/v3/SettlementReport": {
-      "get": {
+      "post": {
         "tags": [
           "SettlementReport"
         ],
@@ -136,6 +136,14 @@
             "in": "query",
             "schema": {
               "description": "Defines the wholesale calculation type",
+              "x-enumNames": [
+                "BalanceFixing",
+                "Aggregation",
+                "WholesaleFixing",
+                "FirstCorrectionSettlement",
+                "SecondCorrectionSettlement",
+                "ThirdCorrectionSettlement"
+              ],
               "allOf": [
                 {
                   "$ref": "#/components/schemas/CalculationType"
@@ -143,16 +151,6 @@
               ]
             }
           },
-          {
-            "name": "gridAreaCodes",
-            "in": "query",
-            "schema": {
-              "type": "array",
-              "items": {
-                "type": "string"
-              }
-            }
-          },
           {
             "name": "periodStart",
             "in": "query",
@@ -170,6 +168,34 @@
             }
           }
         ],
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "array",
+                "items": {
+                  "type": "string"
+                }
+              }
+            },
+            "text/json": {
+              "schema": {
+                "type": "array",
+                "items": {
+                  "type": "string"
+                }
+              }
+            },
+            "application/*+json": {
+              "schema": {
+                "type": "array",
+                "items": {
+                  "type": "string"
+                }
+              }
+            }
+          }
+        },
         "responses": {
           "200": {
             "description": "OK",
@@ -233,6 +259,18 @@
             "nullable": true
           },
           "orchestrationState": {
+            "x-enumNames": [
+              "Scheduled",
+              "Calculating",
+              "Calculated",
+              "CalculationFailed",
+              "ActorMessagesEnqueuing",
+              "ActorMessagesEnqueued",
+              "ActorMessagesEnqueuingFailed",
+              "Completed",
+              "Canceled",
+              "Started"
+            ],
             "allOf": [
               {
                 "$ref": "#/components/schemas/CalculationOrchestrationState"
@@ -250,6 +288,14 @@
           },
           "calculationType": {
             "description": "Defines the wholesale calculation type",
+            "x-enumNames": [
+              "BalanceFixing",
+              "Aggregation",
+              "WholesaleFixing",
+              "FirstCorrectionSettlement",
+              "SecondCorrectionSettlement",
+              "ThirdCorrectionSettlement"
+            ],
             "allOf": [
               {
                 "$ref": "#/components/schemas/CalculationType"
@@ -272,6 +318,18 @@
       },
       "CalculationOrchestrationState": {
         "type": "string",
+        "x-enumNames": [
+          "Scheduled",
+          "Calculating",
+          "Calculated",
+          "CalculationFailed",
+          "ActorMessagesEnqueuing",
+          "ActorMessagesEnqueued",
+          "ActorMessagesEnqueuingFailed",
+          "Completed",
+          "Canceled",
+          "Started"
+        ],
         "enum": [
           "Scheduled",
           "Calculating",
@@ -287,6 +345,12 @@
       },
       "CalculationState": {
         "type": "string",
+        "x-enumNames": [
+          "Pending",
+          "Executing",
+          "Completed",
+          "Failed"
+        ],
         "enum": [
           "Pending",
           "Executing",
@@ -297,6 +361,14 @@
       "CalculationType": {
         "type": "string",
         "description": "Defines the wholesale calculation type",
+        "x-enumNames": [
+          "BalanceFixing",
+          "Aggregation",
+          "WholesaleFixing",
+          "FirstCorrectionSettlement",
+          "SecondCorrectionSettlement",
+          "ThirdCorrectionSettlement"
+        ],
         "enum": [
           "BalanceFixing",
           "Aggregation",
diff --git a/apps/dh/api-dh/source/DataHub.WebApi/GraphQL/Query/SettlementReportsQuery.cs b/apps/dh/api-dh/source/DataHub.WebApi/GraphQL/Query/SettlementReportsQuery.cs
index cd35eef602..954b9b69b1 100644
--- a/apps/dh/api-dh/source/DataHub.WebApi/GraphQL/Query/SettlementReportsQuery.cs
+++ b/apps/dh/api-dh/source/DataHub.WebApi/GraphQL/Query/SettlementReportsQuery.cs
@@ -74,9 +74,9 @@ public async Task<Dictionary<string, List<RequestSettlementReportGridAreaCalcula
         var gridAreaCalculations = new Dictionary<string, List<RequestSettlementReportGridAreaCalculation>>();
         var calculations = await client.GetApplicableCalculationsAsync(
             calculationType,
-            gridAreaId,
             calculationPeriod.Start.ToDateTimeOffset(),
-            calculationPeriod.End.ToDateTimeOffset());
+            calculationPeriod.End.ToDateTimeOffset(),
+            gridAreaId);
 
         foreach (var calculation in calculations)
         {