diff --git a/x-pack/plugins/apm/typings/numeral.d.ts b/x-pack/plugins/apm/typings/numeral.d.ts
index f08f99f5ef11a1..da2d84662a09fa 100644
--- a/x-pack/plugins/apm/typings/numeral.d.ts
+++ b/x-pack/plugins/apm/typings/numeral.d.ts
@@ -7,6 +7,7 @@
 interface Numeral {
   (value?: unknown): Numeral;
   format: (pattern: string) => string;
+  unformat: (pattern: string) => number;
 }
 
 declare var numeral: Numeral;
diff --git a/x-pack/plugins/reporting/index.js b/x-pack/plugins/reporting/index.js
index 1ef8edbc5f921b..014a38bc2066b8 100644
--- a/x-pack/plugins/reporting/index.js
+++ b/x-pack/plugins/reporting/index.js
@@ -15,6 +15,7 @@ import { createQueueFactory } from './server/lib/create_queue';
 import { config as appConfig } from './server/config/config';
 import { checkLicenseFactory } from './server/lib/check_license';
 import { validateConfig } from './server/lib/validate_config';
+import { validateMaxContentLength } from './server/lib/validate_max_content_length';
 import { exportTypesRegistryFactory } from './server/lib/export_types_registry';
 import { PHANTOM, createBrowserDriverFactory, getDefaultBrowser, getDefaultChromiumSandboxDisabled } from './server/browsers';
 import { logConfiguration } from './log_configuration';
@@ -148,7 +149,10 @@ export const reporting = (kibana) => {
       server.expose('exportTypesRegistry', exportTypesRegistry);
 
       const config = server.config();
-      validateConfig(config, message => server.log(['reporting', 'warning'], message));
+      const logWarning = message => server.log(['reporting', 'warning'], message);
+
+      validateConfig(config, logWarning);
+      validateMaxContentLength(server, logWarning);
       logConfiguration(config, message => server.log(['reporting', 'debug'], message));
 
       const { xpack_main: xpackMainPlugin } = server.plugins;
diff --git a/x-pack/plugins/reporting/server/lib/__tests__/validate_max_content_length.js b/x-pack/plugins/reporting/server/lib/__tests__/validate_max_content_length.js
new file mode 100644
index 00000000000000..28ac7bade95c1f
--- /dev/null
+++ b/x-pack/plugins/reporting/server/lib/__tests__/validate_max_content_length.js
@@ -0,0 +1,71 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+import expect from 'expect.js';
+import sinon from 'sinon';
+import { validateMaxContentLength } from '../validate_max_content_length';
+
+const FIVE_HUNDRED_MEGABYTES = 524288000;
+const ONE_HUNDRED_MEGABYTES = 104857600;
+
+describe('Reporting: Validate Max Content Length', () => {
+  const log = sinon.spy();
+
+  beforeEach(() => {
+    log.resetHistory();
+  });
+
+  it('should log warning messages when reporting has a higher max-size than elasticsearch', async () => {
+    const server = {
+      config: () => ({
+        get: sinon.stub().returns(FIVE_HUNDRED_MEGABYTES),
+      }),
+      plugins: {
+        elasticsearch: {
+          getCluster: () => ({
+            callWithInternalUser: () => ({
+              defaults: {
+                http: {
+                  max_content_length: '100mb',
+                },
+              },
+            }),
+          }),
+        },
+      },
+    };
+
+    await validateMaxContentLength(server, log);
+
+    sinon.assert.calledWithMatch(log, `xpack.reporting.csv.maxSizeBytes (524288000) is higher`);
+    sinon.assert.calledWithMatch(log, `than ElasticSearch's http.max_content_length (104857600)`);
+    sinon.assert.calledWithMatch(log, 'Please set http.max_content_length in ElasticSearch to match');
+    sinon.assert.calledWithMatch(log, 'or lower your xpack.reporting.csv.maxSizeBytes in Kibana');
+  });
+
+  it('should do nothing when reporting has the same max-size as elasticsearch', async () => {
+    const server = {
+      config: () => ({
+        get: sinon.stub().returns(ONE_HUNDRED_MEGABYTES),
+      }),
+      plugins: {
+        elasticsearch: {
+          getCluster: () => ({
+            callWithInternalUser: () => ({
+              defaults: {
+                http: {
+                  max_content_length: '100mb',
+                },
+              },
+            }),
+          }),
+        },
+      },
+    };
+
+    expect(async () => validateMaxContentLength(server, log)).not.to.throwError();
+    sinon.assert.notCalled(log);
+  });
+});
diff --git a/x-pack/plugins/reporting/server/lib/validate_max_content_length.ts b/x-pack/plugins/reporting/server/lib/validate_max_content_length.ts
new file mode 100644
index 00000000000000..0142b482bc0aaf
--- /dev/null
+++ b/x-pack/plugins/reporting/server/lib/validate_max_content_length.ts
@@ -0,0 +1,31 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+import numeral from '@elastic/numeral';
+import { defaults, get } from 'lodash';
+const KIBANA_MAX_SIZE_BYTES_PATH = 'xpack.reporting.csv.maxSizeBytes';
+const ES_MAX_SIZE_BYTES_PATH = 'http.max_content_length';
+
+export async function validateMaxContentLength(server: any, log: (message: string) => any) {
+  const config = server.config();
+  const { callWithInternalUser } = server.plugins.elasticsearch.getCluster('data');
+
+  const elasticClusterSettingsResponse = await callWithInternalUser('cluster.getSettings', {
+    includeDefaults: true,
+  });
+  const { persistent, transient, defaults: defaultSettings } = elasticClusterSettingsResponse;
+  const elasticClusterSettings = defaults({}, persistent, transient, defaultSettings);
+
+  const elasticSearchMaxContent = get(elasticClusterSettings, 'http.max_content_length', '100mb');
+  const elasticSearchMaxContentBytes = numeral().unformat(elasticSearchMaxContent.toUpperCase());
+  const kibanaMaxContentBytes = config.get(KIBANA_MAX_SIZE_BYTES_PATH);
+
+  if (kibanaMaxContentBytes > elasticSearchMaxContentBytes) {
+    log(
+      `${KIBANA_MAX_SIZE_BYTES_PATH} (${kibanaMaxContentBytes}) is higher than ElasticSearch's ${ES_MAX_SIZE_BYTES_PATH} (${elasticSearchMaxContentBytes}). ` +
+        `Please set ${ES_MAX_SIZE_BYTES_PATH} in ElasticSearch to match, or lower your ${KIBANA_MAX_SIZE_BYTES_PATH} in Kibana to avoid this warning.`
+    );
+  }
+}