diff --git a/fineract-accounting/src/main/java/org/apache/fineract/accounting/financialactivityaccount/api/FinancialActivityAccountsApiResource.java b/fineract-accounting/src/main/java/org/apache/fineract/accounting/financialactivityaccount/api/FinancialActivityAccountsApiResource.java
index ee7f9ba62..4a35cf53d 100644
--- a/fineract-accounting/src/main/java/org/apache/fineract/accounting/financialactivityaccount/api/FinancialActivityAccountsApiResource.java
+++ b/fineract-accounting/src/main/java/org/apache/fineract/accounting/financialactivityaccount/api/FinancialActivityAccountsApiResource.java
@@ -40,6 +40,7 @@ import jakarta.ws.rs.core.UriInfo;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
 import org.apache.fineract.accounting.financialactivityaccount.data.FinancialActivityAccountData;
+import org.apache.fineract.accounting.financialactivityaccount.data.request.FinancialActivityAccRequest;
 import org.apache.fineract.accounting.financialactivityaccount.service.FinancialActivityAccountReadPlatformService;
 import org.apache.fineract.commands.domain.CommandWrapper;
 import org.apache.fineract.commands.service.CommandWrapperBuilder;
@@ -77,16 +78,9 @@ public class FinancialActivityAccountsApiResource {
     @Path("template")
     @Consumes({ MediaType.APPLICATION_JSON })
     @Produces({ MediaType.APPLICATION_JSON })
-    public String retrieveTemplate(@Context final UriInfo uriInfo) {
-
-        this.context.authenticatedUser().validateHasReadPermission(FinancialActivityAccountsConstants.resourceNameForPermission);
-
-        FinancialActivityAccountData financialActivityAccountData = this.financialActivityAccountReadPlatformService
-                .getFinancialActivityAccountTemplate();
-
-        final ApiRequestJsonSerializationSettings settings = this.apiRequestParameterHelper.process(uriInfo.getQueryParameters());
-        return this.apiJsonSerializerService.serialize(settings, financialActivityAccountData,
-                FinancialActivityAccountsConstants.RESPONSE_DATA_PARAMETERS);
+    public FinancialActivityAccountData retrieveTemplate() {
+        context.authenticatedUser().validateHasReadPermission(FinancialActivityAccountsConstants.resourceNameForPermission);
+        return financialActivityAccountReadPlatformService.getFinancialActivityAccountTemplate();
     }
 
     @GET
@@ -96,14 +90,9 @@ public class FinancialActivityAccountsApiResource {
             Example Requests:
             financialactivityaccounts""")
     @ApiResponse(responseCode = "200", description = "OK", content = @Content(array = @ArraySchema(schema = @Schema(implementation = FinancialActivityAccountsApiResourceSwagger.GetFinancialActivityAccountsResponse.class))))
-    public String retrieveAll(@Context final UriInfo uriInfo) {
-
-        this.context.authenticatedUser().validateHasReadPermission(FinancialActivityAccountsConstants.resourceNameForPermission);
-        final List<FinancialActivityAccountData> financialActivityAccounts = this.financialActivityAccountReadPlatformService.retrieveAll();
-
-        final ApiRequestJsonSerializationSettings settings = this.apiRequestParameterHelper.process(uriInfo.getQueryParameters());
-        return this.apiJsonSerializerService.serialize(settings, financialActivityAccounts,
-                FinancialActivityAccountsConstants.RESPONSE_DATA_PARAMETERS);
+    public List<FinancialActivityAccountData> retrieveAll() {
+        context.authenticatedUser().validateHasReadPermission(FinancialActivityAccountsConstants.resourceNameForPermission);
+        return financialActivityAccountReadPlatformService.retrieveAll();
     }
 
     @GET
@@ -114,20 +103,17 @@ public class FinancialActivityAccountsApiResource {
             Example Requests:
             financialactivityaccounts/1""")
     @ApiResponse(responseCode = "200", description = "OK", content = @Content(schema = @Schema(implementation = FinancialActivityAccountsApiResourceSwagger.GetFinancialActivityAccountsResponse.class)))
-    public String retreive(@PathParam("mappingId") @Parameter(description = "mappingId") final Long mappingId,
+    public FinancialActivityAccountData retreive(@PathParam("mappingId") @Parameter(description = "mappingId") final Long mappingId,
             @Context final UriInfo uriInfo) {
+        context.authenticatedUser().validateHasReadPermission(FinancialActivityAccountsConstants.resourceNameForPermission);
 
-        this.context.authenticatedUser().validateHasReadPermission(FinancialActivityAccountsConstants.resourceNameForPermission);
-
-        final ApiRequestJsonSerializationSettings settings = this.apiRequestParameterHelper.process(uriInfo.getQueryParameters());
-        FinancialActivityAccountData financialActivityAccountData = this.financialActivityAccountReadPlatformService.retrieve(mappingId);
+        final ApiRequestJsonSerializationSettings settings = apiRequestParameterHelper.process(uriInfo.getQueryParameters());
+        FinancialActivityAccountData financialActivityAccountData = financialActivityAccountReadPlatformService.retrieve(mappingId);
         if (settings.isTemplate()) {
-            financialActivityAccountData = this.financialActivityAccountReadPlatformService
-                    .addTemplateDetails(financialActivityAccountData);
+            financialActivityAccountData = financialActivityAccountReadPlatformService.addTemplateDetails(financialActivityAccountData);
         }
 
-        return this.apiJsonSerializerService.serialize(settings, financialActivityAccountData,
-                FinancialActivityAccountsConstants.RESPONSE_DATA_PARAMETERS);
+        return financialActivityAccountData;
     }
 
     @POST
@@ -138,14 +124,11 @@ public class FinancialActivityAccountsApiResource {
             financialActivityId, glAccountId""")
     @RequestBody(content = @Content(schema = @Schema(implementation = FinancialActivityAccountsApiResourceSwagger.PostFinancialActivityAccountsRequest.class)))
     @ApiResponse(responseCode = "200", description = "OK", content = @Content(schema = @Schema(implementation = FinancialActivityAccountsApiResourceSwagger.PostFinancialActivityAccountsResponse.class)))
-    public String createGLAccount(@Parameter(hidden = true) final String jsonRequestBody) {
+    public CommandProcessingResult createGLAccount(@Parameter(hidden = true) FinancialActivityAccRequest activityAccRequest) {
+        final CommandWrapper commandRequest = new CommandWrapperBuilder().createOfficeToGLAccountMapping()
+                .withJson(apiJsonSerializerService.serialize(activityAccRequest)).build();
 
-        final CommandWrapper commandRequest = new CommandWrapperBuilder().createOfficeToGLAccountMapping().withJson(jsonRequestBody)
-                .build();
-
-        final CommandProcessingResult result = this.commandsSourceWritePlatformService.logCommandSource(commandRequest);
-
-        return this.apiJsonSerializerService.serialize(result);
+        return commandsSourceWritePlatformService.logCommandSource(commandRequest);
     }
 
     @PUT
@@ -155,15 +138,12 @@ public class FinancialActivityAccountsApiResource {
     @Operation(summary = "Update a Financial Activity to Account Mapping", description = "the API updates the Ledger account linked to a Financial Activity")
     @RequestBody(content = @Content(schema = @Schema(implementation = FinancialActivityAccountsApiResourceSwagger.PostFinancialActivityAccountsRequest.class)))
     @ApiResponse(responseCode = "200", description = "OK", content = @Content(schema = @Schema(implementation = FinancialActivityAccountsApiResourceSwagger.PutFinancialActivityAccountsResponse.class)))
-    public String updateGLAccount(@PathParam("mappingId") @Parameter(description = "mappingId") final Long mappingId,
-            @Parameter(hidden = true) final String jsonRequestBody) {
-
+    public CommandProcessingResult updateGLAccount(@PathParam("mappingId") @Parameter(description = "mappingId") final Long mappingId,
+            @Parameter(hidden = true) FinancialActivityAccRequest activityAccRequest) {
         final CommandWrapper commandRequest = new CommandWrapperBuilder().updateOfficeToGLAccountMapping(mappingId)
-                .withJson(jsonRequestBody).build();
+                .withJson(apiJsonSerializerService.serialize(activityAccRequest)).build();
 
-        final CommandProcessingResult result = this.commandsSourceWritePlatformService.logCommandSource(commandRequest);
-
-        return this.apiJsonSerializerService.serialize(result);
+        return commandsSourceWritePlatformService.logCommandSource(commandRequest);
     }
 
     @DELETE
@@ -172,12 +152,8 @@ public class FinancialActivityAccountsApiResource {
     @Produces({ MediaType.APPLICATION_JSON })
     @Operation(summary = "Delete a Financial Activity to Account Mapping")
     @ApiResponse(responseCode = "200", description = "OK", content = @Content(schema = @Schema(implementation = FinancialActivityAccountsApiResourceSwagger.DeleteFinancialActivityAccountsResponse.class)))
-    public String deleteGLAccount(@PathParam("mappingId") @Parameter(description = "mappingId") final Long mappingId) {
-
+    public CommandProcessingResult deleteGLAccount(@PathParam("mappingId") @Parameter(description = "mappingId") final Long mappingId) {
         final CommandWrapper commandRequest = new CommandWrapperBuilder().deleteOfficeToGLAccountMapping(mappingId).build();
-
-        final CommandProcessingResult result = this.commandsSourceWritePlatformService.logCommandSource(commandRequest);
-
-        return this.apiJsonSerializerService.serialize(result);
+        return commandsSourceWritePlatformService.logCommandSource(commandRequest);
     }
 }
diff --git a/fineract-accounting/src/main/java/org/apache/fineract/accounting/financialactivityaccount/data/request/FinancialActivityAccRequest.java b/fineract-accounting/src/main/java/org/apache/fineract/accounting/financialactivityaccount/data/request/FinancialActivityAccRequest.java
new file mode 100644
index 000000000..9c81886ed
--- /dev/null
+++ b/fineract-accounting/src/main/java/org/apache/fineract/accounting/financialactivityaccount/data/request/FinancialActivityAccRequest.java
@@ -0,0 +1,28 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.fineract.accounting.financialactivityaccount.data.request;
+
+import java.io.Serial;
+import java.io.Serializable;
+
+public record FinancialActivityAccRequest(Long financialActivityId, Long glAccountId) implements Serializable {
+
+    @Serial
+    private static final long serialVersionUID = 1L;
+}