diff --git a/x-pack/plugins/apm/common/rules/schema.ts b/x-pack/plugins/apm/common/rules/schema.ts
index 7e48ad989b606..698b4507c5b3f 100644
--- a/x-pack/plugins/apm/common/rules/schema.ts
+++ b/x-pack/plugins/apm/common/rules/schema.ts
@@ -15,6 +15,7 @@ export const errorCountParamsSchema = schema.object({
   threshold: schema.number(),
   serviceName: schema.maybe(schema.string()),
   environment: schema.string(),
+  errorGroupingKey: schema.maybe(schema.string()),
 });
 
 export const transactionDurationParamsSchema = schema.object({
diff --git a/x-pack/plugins/apm/public/components/alerting/rule_types/error_count_rule_type/index.tsx b/x-pack/plugins/apm/public/components/alerting/rule_types/error_count_rule_type/index.tsx
index 09ca441cd26e9..f23dc6f4fb362 100644
--- a/x-pack/plugins/apm/public/components/alerting/rule_types/error_count_rule_type/index.tsx
+++ b/x-pack/plugins/apm/public/components/alerting/rule_types/error_count_rule_type/index.tsx
@@ -21,6 +21,7 @@ import { createCallApmApi } from '../../../../services/rest/create_call_apm_api'
 import { ChartPreview } from '../../ui_components/chart_preview';
 import {
   EnvironmentField,
+  ErrorGroupingKeyField,
   IsAboveField,
   ServiceField,
 } from '../../utils/fields';
@@ -33,6 +34,7 @@ export interface RuleParams {
   threshold?: number;
   serviceName?: string;
   environment?: string;
+  errorGroupingKey?: string;
 }
 
 interface Props {
@@ -74,6 +76,7 @@ export function ErrorCountRuleType(props: Props) {
               query: {
                 environment: params.environment,
                 serviceName: params.serviceName,
+                errorGroupingKey: params.errorGroupingKey,
                 interval,
                 start,
                 end,
@@ -88,6 +91,7 @@ export function ErrorCountRuleType(props: Props) {
       params.windowUnit,
       params.environment,
       params.serviceName,
+      params.errorGroupingKey,
     ]
   );
 
@@ -98,6 +102,7 @@ export function ErrorCountRuleType(props: Props) {
         if (value !== params.serviceName) {
           setRuleParams('serviceName', value);
           setRuleParams('environment', ENVIRONMENT_ALL.value);
+          setRuleParams('errorGroupingKey', undefined);
         }
       }}
     />,
@@ -106,6 +111,12 @@ export function ErrorCountRuleType(props: Props) {
       onChange={(value) => setRuleParams('environment', value)}
       serviceName={params.serviceName}
     />,
+    <ErrorGroupingKeyField
+      currentValue={params.errorGroupingKey}
+      onChange={(value) => setRuleParams('errorGroupingKey', value)}
+      serviceName={params.serviceName}
+    />,
+
     <IsAboveField
       value={params.threshold}
       unit={i18n.translate('xpack.apm.errorCountRuleType.errors', {
diff --git a/x-pack/plugins/apm/public/components/alerting/utils/fields.tsx b/x-pack/plugins/apm/public/components/alerting/utils/fields.tsx
index 78437f2ea027b..826a28b06c659 100644
--- a/x-pack/plugins/apm/public/components/alerting/utils/fields.tsx
+++ b/x-pack/plugins/apm/public/components/alerting/utils/fields.tsx
@@ -9,6 +9,7 @@ import { EuiFieldNumber } from '@elastic/eui';
 import { i18n } from '@kbn/i18n';
 import React from 'react';
 import {
+  ERROR_GROUP_ID,
   SERVICE_ENVIRONMENT,
   SERVICE_NAME,
   TRANSACTION_TYPE,
@@ -178,6 +179,45 @@ export function TransactionTypeField({
   );
 }
 
+export function ErrorGroupingKeyField({
+  currentValue,
+  onChange,
+  serviceName,
+}: {
+  currentValue?: string;
+  onChange: (value?: string) => void;
+  serviceName?: string;
+}) {
+  const label = i18n.translate('xpack.apm.alerting.fields.error.group.id', {
+    defaultMessage: 'Error grouping key',
+  });
+  return (
+    <PopoverExpression value={currentValue || allOptionText} title={label}>
+      <SuggestionsSelect
+        customOptions={[{ label: allOptionText, value: undefined }]}
+        customOptionText={i18n.translate(
+          'xpack.apm.errorKeySelectCustomOptionText',
+          {
+            defaultMessage: 'Add \\{searchValue\\} as a new error grouping key',
+          }
+        )}
+        defaultValue={currentValue}
+        fieldName={ERROR_GROUP_ID}
+        onChange={onChange}
+        placeholder={i18n.translate(
+          'xpack.apm.errorGroupingKeySelectPlaceholder',
+          {
+            defaultMessage: 'Select error grouping key',
+          }
+        )}
+        start={moment().subtract(24, 'h').toISOString()}
+        end={moment().toISOString()}
+        serviceName={serviceName}
+      />
+    </PopoverExpression>
+  );
+}
+
 export function IsAboveField({
   value,
   unit,
diff --git a/x-pack/plugins/apm/server/routes/alerts/action_variables.ts b/x-pack/plugins/apm/server/routes/alerts/action_variables.ts
index 471d2ff3141b0..1bb9c41546cf8 100644
--- a/x-pack/plugins/apm/server/routes/alerts/action_variables.ts
+++ b/x-pack/plugins/apm/server/routes/alerts/action_variables.ts
@@ -94,4 +94,13 @@ export const apmActionVariables = {
     name: 'viewInAppUrl' as const,
     usesPublicBaseUrl: true,
   },
+  errorGroupingKey: {
+    description: i18n.translate(
+      'xpack.apm.alerts.action_variables.errorGroupingKey',
+      {
+        defaultMessage: 'The error grouping key the alert is created for',
+      }
+    ),
+    name: 'errorGroupingKey' as const,
+  },
 };
diff --git a/x-pack/plugins/apm/server/routes/alerts/route.ts b/x-pack/plugins/apm/server/routes/alerts/route.ts
index 314e05fed539a..13b790155520f 100644
--- a/x-pack/plugins/apm/server/routes/alerts/route.ts
+++ b/x-pack/plugins/apm/server/routes/alerts/route.ts
@@ -28,6 +28,7 @@ const alertParamsRt = t.intersection([
       t.literal(AggregationType.P99),
     ]),
     serviceName: t.string,
+    errorGroupingKey: t.string,
     transactionType: t.string,
     transactionName: t.string,
   }),
diff --git a/x-pack/plugins/apm/server/routes/alerts/rule_types/error_count/get_error_count_chart_preview.ts b/x-pack/plugins/apm/server/routes/alerts/rule_types/error_count/get_error_count_chart_preview.ts
index 6175b2578a236..59ae52eab6a5a 100644
--- a/x-pack/plugins/apm/server/routes/alerts/rule_types/error_count/get_error_count_chart_preview.ts
+++ b/x-pack/plugins/apm/server/routes/alerts/rule_types/error_count/get_error_count_chart_preview.ts
@@ -7,7 +7,10 @@
 
 import { rangeQuery, termQuery } from '@kbn/observability-plugin/server';
 import { ProcessorEvent } from '@kbn/observability-plugin/common';
-import { SERVICE_NAME } from '../../../../../common/es_fields/apm';
+import {
+  ERROR_GROUP_ID,
+  SERVICE_NAME,
+} from '../../../../../common/es_fields/apm';
 import { AlertParams } from '../../route';
 import { environmentQuery } from '../../../../../common/utils/environment_query';
 import { APMEventClient } from '../../../../lib/helpers/create_es_client/create_apm_event_client';
@@ -24,12 +27,14 @@ export async function getTransactionErrorCountChartPreview({
   apmEventClient: APMEventClient;
   alertParams: AlertParams;
 }): Promise<TransactionErrorCountChartPreviewResponse> {
-  const { serviceName, environment, interval, start, end } = alertParams;
+  const { serviceName, environment, errorGroupingKey, interval, start, end } =
+    alertParams;
 
   const query = {
     bool: {
       filter: [
         ...termQuery(SERVICE_NAME, serviceName),
+        ...termQuery(ERROR_GROUP_ID, errorGroupingKey),
         ...rangeQuery(start, end),
         ...environmentQuery(environment),
       ],
diff --git a/x-pack/plugins/apm/server/routes/alerts/rule_types/error_count/register_error_count_rule_type.ts b/x-pack/plugins/apm/server/routes/alerts/rule_types/error_count/register_error_count_rule_type.ts
index a008dd0d23cb3..2527a11e3f001 100644
--- a/x-pack/plugins/apm/server/routes/alerts/rule_types/error_count/register_error_count_rule_type.ts
+++ b/x-pack/plugins/apm/server/routes/alerts/rule_types/error_count/register_error_count_rule_type.ts
@@ -25,6 +25,7 @@ import {
   getEnvironmentLabel,
 } from '../../../../../common/environment_filter_values';
 import {
+  ERROR_GROUP_ID,
   PROCESSOR_EVENT,
   SERVICE_ENVIRONMENT,
   SERVICE_NAME,
@@ -77,6 +78,7 @@ export function registerErrorCountRuleType({
           apmActionVariables.interval,
           apmActionVariables.reason,
           apmActionVariables.serviceName,
+          apmActionVariables.errorGroupingKey,
           apmActionVariables.threshold,
           apmActionVariables.triggerValue,
           apmActionVariables.viewInAppUrl,
@@ -112,6 +114,7 @@ export function registerErrorCountRuleType({
                   },
                   { term: { [PROCESSOR_EVENT]: ProcessorEvent.error } },
                   ...termQuery(SERVICE_NAME, ruleParams.serviceName),
+                  ...termQuery(ERROR_GROUP_ID, ruleParams.errorGroupingKey),
                   ...environmentQuery(ruleParams.environment),
                 ],
               },
@@ -164,7 +167,12 @@ export function registerErrorCountRuleType({
               windowUnit: ruleParams.windowUnit,
             });
 
-            const id = [ApmRuleType.ErrorCount, serviceName, environment]
+            const id = [
+              ApmRuleType.ErrorCount,
+              serviceName,
+              environment,
+              ruleParams.errorGroupingKey,
+            ]
               .filter((name) => name)
               .join('_');
 
@@ -188,6 +196,7 @@ export function registerErrorCountRuleType({
                   [PROCESSOR_EVENT]: ProcessorEvent.error,
                   [ALERT_EVALUATION_VALUE]: errorCount,
                   [ALERT_EVALUATION_THRESHOLD]: ruleParams.threshold,
+                  [ERROR_GROUP_ID]: ruleParams.errorGroupingKey,
                   [ALERT_REASON]: alertReason,
                   ...sourceFields,
                 },
@@ -201,6 +210,7 @@ export function registerErrorCountRuleType({
                 reason: alertReason,
                 serviceName,
                 threshold: ruleParams.threshold,
+                errorGroupingKey: ruleParams.errorGroupingKey,
                 triggerValue: errorCount,
                 viewInAppUrl,
               });
diff --git a/x-pack/test/apm_api_integration/tests/alerts/chart_preview.spec.ts b/x-pack/test/apm_api_integration/tests/alerts/chart_preview.spec.ts
index f070098a66661..7ec09849b7ff2 100644
--- a/x-pack/test/apm_api_integration/tests/alerts/chart_preview.spec.ts
+++ b/x-pack/test/apm_api_integration/tests/alerts/chart_preview.spec.ts
@@ -100,6 +100,33 @@ export default function ApiTest({ getService }: FtrProviderContext) {
       ).to.equal(true);
     });
 
+    it('error_count with error grouping key', async () => {
+      const options = {
+        params: {
+          query: {
+            start,
+            end,
+            serviceName: 'opbeans-java',
+            errorGroupingKey: 'd16d39e7fa133b8943cea035430a7b4e',
+            environment: 'ENVIRONMENT_ALL',
+            interval: '5m',
+          },
+        },
+      };
+
+      const response = await apmApiClient.readUser({
+        endpoint: 'GET /internal/apm/rule_types/error_count/chart_preview',
+        ...options,
+      });
+
+      expect(response.status).to.be(200);
+      expect(response.body.errorCountChartPreview).to.eql([
+        { x: 1627974600000, y: 4 },
+        { x: 1627974900000, y: 2 },
+        { x: 1627975200000, y: 0 },
+      ]);
+    });
+
     it('transaction_duration (with data)', async () => {
       const options = getOptions();
       const response = await apmApiClient.readUser({