diff --git a/x-pack/plugins/apm/public/components/alerting/register_apm_alerts.ts b/x-pack/plugins/apm/public/components/alerting/register_apm_alerts.ts
index 306c8e32ef6be..5407c32c882ae 100644
--- a/x-pack/plugins/apm/public/components/alerting/register_apm_alerts.ts
+++ b/x-pack/plugins/apm/public/components/alerting/register_apm_alerts.ts
@@ -31,7 +31,7 @@ export function registerApmAlerts(
 - Service name: \\{\\{context.serviceName\\}\\}
 - Environment: \\{\\{context.environment\\}\\}
 - Threshold: \\{\\{context.threshold\\}\\} errors
-- Triggered value: \\{\\{context.triggerValue\\}\\} errors over the last \\{\\{context.intervalSize\\}\\}\\{\\{context.intervalUnit\\}\\}`,
+- Triggered value: \\{\\{context.triggerValue\\}\\} errors over the last \\{\\{context.interval\\}\\}`,
       }
     ),
   });
@@ -58,7 +58,7 @@ export function registerApmAlerts(
 - Type: \\{\\{context.transactionType\\}\\}
 - Environment: \\{\\{context.environment\\}\\}
 - Threshold: \\{\\{context.threshold\\}\\}ms
-- Triggered value: \\{\\{context.triggerValue\\}\\} over the last \\{\\{context.intervalSize\\}\\}\\{\\{context.intervalUnit\\}\\}`,
+- Triggered value: \\{\\{context.triggerValue\\}\\} over the last \\{\\{context.interval\\}\\}`,
       }
     ),
   });
@@ -85,7 +85,7 @@ export function registerApmAlerts(
 - Type: \\{\\{context.transactionType\\}\\}
 - Environment: \\{\\{context.environment\\}\\}
 - Threshold: \\{\\{context.threshold\\}\\}%
-- Triggered value: \\{\\{context.triggerValue\\}\\}% of errors over the last \\{\\{context.intervalSize\\}\\}\\{\\{context.intervalUnit\\}\\}`,
+- Triggered value: \\{\\{context.triggerValue\\}\\}% of errors over the last \\{\\{context.interval\\}\\}`,
       }
     ),
   });
diff --git a/x-pack/plugins/apm/server/lib/alerts/action_variables.ts b/x-pack/plugins/apm/server/lib/alerts/action_variables.ts
index 6361279b3437c..19af337e18811 100644
--- a/x-pack/plugins/apm/server/lib/alerts/action_variables.ts
+++ b/x-pack/plugins/apm/server/lib/alerts/action_variables.ts
@@ -45,24 +45,14 @@ export const apmActionVariables = {
     ),
     name: 'triggerValue',
   },
-  windowSize: {
+  interval: {
     description: i18n.translate(
       'xpack.apm.alerts.action_variables.intervalSize',
       {
         defaultMessage:
-          'The interval size the alert will use to check for any incident',
+          'The length and unit of the time period where the alert conditions were met',
       }
     ),
-    name: 'intervalSize',
-  },
-  windowUnit: {
-    description: i18n.translate(
-      'xpack.apm.alerts.action_variables.intervalUnit',
-      {
-        defaultMessage:
-          'The interval unit the alert will use to check for any incident',
-      }
-    ),
-    name: 'intervalUnit',
+    name: 'interval',
   },
 };
diff --git a/x-pack/plugins/apm/server/lib/alerts/register_error_count_alert_type.test.ts b/x-pack/plugins/apm/server/lib/alerts/register_error_count_alert_type.test.ts
index ca121a40d4d32..8dbc8054d4371 100644
--- a/x-pack/plugins/apm/server/lib/alerts/register_error_count_alert_type.test.ts
+++ b/x-pack/plugins/apm/server/lib/alerts/register_error_count_alert_type.test.ts
@@ -117,32 +117,28 @@ describe('Error count alert', () => {
       environment: 'env-foo',
       threshold: 1,
       triggerValue: 2,
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
     expect(scheduleActions).toHaveBeenCalledWith('threshold_met', {
       serviceName: 'foo',
       environment: 'env-foo-2',
       threshold: 1,
       triggerValue: 2,
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
     expect(scheduleActions).toHaveBeenCalledWith('threshold_met', {
       serviceName: 'bar',
       environment: 'env-bar',
       threshold: 1,
       triggerValue: 2,
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
     expect(scheduleActions).toHaveBeenCalledWith('threshold_met', {
       serviceName: 'bar',
       environment: 'env-bar-2',
       threshold: 1,
       triggerValue: 2,
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
   });
   it('sends alerts with service name', async () => {
@@ -194,16 +190,14 @@ describe('Error count alert', () => {
       environment: undefined,
       threshold: 1,
       triggerValue: 2,
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
     expect(scheduleActions).toHaveBeenCalledWith('threshold_met', {
       serviceName: 'bar',
       environment: undefined,
       threshold: 1,
       triggerValue: 2,
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
   });
 });
diff --git a/x-pack/plugins/apm/server/lib/alerts/register_error_count_alert_type.ts b/x-pack/plugins/apm/server/lib/alerts/register_error_count_alert_type.ts
index 20fbd3db25f4e..7b63f2c354916 100644
--- a/x-pack/plugins/apm/server/lib/alerts/register_error_count_alert_type.ts
+++ b/x-pack/plugins/apm/server/lib/alerts/register_error_count_alert_type.ts
@@ -55,8 +55,7 @@ export function registerErrorCountAlertType({
         apmActionVariables.environment,
         apmActionVariables.threshold,
         apmActionVariables.triggerValue,
-        apmActionVariables.windowSize,
-        apmActionVariables.windowUnit,
+        apmActionVariables.interval,
       ],
     },
     producer: 'apm',
@@ -140,8 +139,7 @@ export function registerErrorCountAlertType({
             environment,
             threshold: alertParams.threshold,
             triggerValue: errorCount,
-            intervalSize: alertParams.windowSize,
-            intervalUnit: alertParams.windowUnit,
+            interval: `${alertParams.windowSize}${alertParams.windowUnit}`,
           });
         }
         response.aggregations?.services.buckets.forEach((serviceBucket) => {
diff --git a/x-pack/plugins/apm/server/lib/alerts/register_transaction_duration_alert_type.ts b/x-pack/plugins/apm/server/lib/alerts/register_transaction_duration_alert_type.ts
index 57201b3f267f1..1d8b664751ba2 100644
--- a/x-pack/plugins/apm/server/lib/alerts/register_transaction_duration_alert_type.ts
+++ b/x-pack/plugins/apm/server/lib/alerts/register_transaction_duration_alert_type.ts
@@ -64,8 +64,7 @@ export function registerTransactionDurationAlertType({
         apmActionVariables.environment,
         apmActionVariables.threshold,
         apmActionVariables.triggerValue,
-        apmActionVariables.windowSize,
-        apmActionVariables.windowUnit,
+        apmActionVariables.interval,
       ],
     },
     producer: 'apm',
@@ -153,8 +152,7 @@ export function registerTransactionDurationAlertType({
             environment,
             threshold,
             triggerValue: transactionDurationFormatted,
-            intervalSize: alertParams.windowSize,
-            intervalUnit: alertParams.windowUnit,
+            interval: `${alertParams.windowSize}${alertParams.windowUnit}`,
           });
         });
       }
diff --git a/x-pack/plugins/apm/server/lib/alerts/register_transaction_error_rate_alert_type.test.ts b/x-pack/plugins/apm/server/lib/alerts/register_transaction_error_rate_alert_type.test.ts
index 207e6108cd83c..7c13f2a17b255 100644
--- a/x-pack/plugins/apm/server/lib/alerts/register_transaction_error_rate_alert_type.test.ts
+++ b/x-pack/plugins/apm/server/lib/alerts/register_transaction_error_rate_alert_type.test.ts
@@ -133,8 +133,7 @@ describe('Transaction error rate alert', () => {
       environment: 'env-foo',
       threshold: 10,
       triggerValue: '50',
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
     expect(scheduleActions).toHaveBeenCalledWith('threshold_met', {
       serviceName: 'foo',
@@ -142,8 +141,7 @@ describe('Transaction error rate alert', () => {
       environment: 'env-foo-2',
       threshold: 10,
       triggerValue: '50',
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
     expect(scheduleActions).toHaveBeenCalledWith('threshold_met', {
       serviceName: 'bar',
@@ -151,8 +149,7 @@ describe('Transaction error rate alert', () => {
       environment: 'env-bar',
       threshold: 10,
       triggerValue: '50',
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
     expect(scheduleActions).toHaveBeenCalledWith('threshold_met', {
       serviceName: 'bar',
@@ -160,8 +157,7 @@ describe('Transaction error rate alert', () => {
       environment: 'env-bar-2',
       threshold: 10,
       triggerValue: '50',
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
   });
   it('sends alerts with service name and transaction type', async () => {
@@ -226,8 +222,7 @@ describe('Transaction error rate alert', () => {
       environment: undefined,
       threshold: 10,
       triggerValue: '50',
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
     expect(scheduleActions).toHaveBeenCalledWith('threshold_met', {
       serviceName: 'bar',
@@ -235,8 +230,7 @@ describe('Transaction error rate alert', () => {
       environment: undefined,
       threshold: 10,
       triggerValue: '50',
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
   });
 
@@ -289,8 +283,7 @@ describe('Transaction error rate alert', () => {
       environment: undefined,
       threshold: 10,
       triggerValue: '50',
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
     expect(scheduleActions).toHaveBeenCalledWith('threshold_met', {
       serviceName: 'bar',
@@ -298,8 +291,7 @@ describe('Transaction error rate alert', () => {
       environment: undefined,
       threshold: 10,
       triggerValue: '50',
-      intervalSize: 5,
-      intervalUnit: 'm',
+      interval: '5m',
     });
   });
 });
diff --git a/x-pack/plugins/apm/server/lib/alerts/register_transaction_error_rate_alert_type.ts b/x-pack/plugins/apm/server/lib/alerts/register_transaction_error_rate_alert_type.ts
index 26a23e33f8730..7bb9894a837f5 100644
--- a/x-pack/plugins/apm/server/lib/alerts/register_transaction_error_rate_alert_type.ts
+++ b/x-pack/plugins/apm/server/lib/alerts/register_transaction_error_rate_alert_type.ts
@@ -60,8 +60,7 @@ export function registerTransactionErrorRateAlertType({
         apmActionVariables.environment,
         apmActionVariables.threshold,
         apmActionVariables.triggerValue,
-        apmActionVariables.windowSize,
-        apmActionVariables.windowUnit,
+        apmActionVariables.interval,
       ],
     },
     producer: 'apm',
@@ -175,8 +174,7 @@ export function registerTransactionErrorRateAlertType({
             triggerValue: String(
               parseFloat(transactionErrorRate.toPrecision(3))
             ),
-            intervalSize: alertParams.windowSize,
-            intervalUnit: alertParams.windowUnit,
+            interval: `${alertParams.windowSize}${alertParams.windowUnit}`,
           });
         }