diff --git a/infrastructure/modules/cloudwatch-metric-alarm/README.md b/infrastructure/modules/cloudwatch-metric-alarm/README.md
index c653cabc..951e18d9 100644
--- a/infrastructure/modules/cloudwatch-metric-alarm/README.md
+++ b/infrastructure/modules/cloudwatch-metric-alarm/README.md
@@ -7,7 +7,7 @@ NHS Screening wrapper around the [terraform-aws-modules/CloudWatch/aws](https://
 | Control | How it is enforced |
 | --- | --- |
 | Naming | Alarm names derived from context.id + alarm suffix |
-| Period | Hardcoded to 60 seconds for consistency |
+| Period | Defaults to 60 seconds; configurable per alarm |
 | Statistic | Defaults to Sum; configurable per alarm |
 | SNS actions | Optional list of topic ARNs for notifications |
 | Missing data | Defaults to `notBreaching` (safe default) |
@@ -33,6 +33,7 @@ module "app_errors_alarm" {
     evaluation_periods = 2
     threshold          = 10
     statistic          = "Sum"
+    period             = 300
   }
 
   alarm_actions = [module.sns.topic_arn]
@@ -53,6 +54,7 @@ module "ecs_task_alarms" {
     comparison_operator = "GreaterThanThreshold"
     evaluation_periods = 3
     threshold          = 80
+    period             = 60
     dimensions = {
       ServiceName = "my-service"
       ClusterName = "my-cluster"
@@ -64,6 +66,8 @@ module "ecs_task_alarms" {
 }
 ```
 
+`period` is optional and defaults to 60 seconds for each alarm. Set it to 3600 seconds for hourly metrics such as AWS License Manager usage. `actions_enabled` also defaults to `true`; set it to `false` when you want alarms to track state without sending configured alarm actions. SNS alarm, recovery, and insufficient-data destinations are configured separately through the corresponding action inputs.
+
 ### Referencing log metric filter output
 
 ```hcl
@@ -97,8 +101,8 @@ module "error_alarm" {
 
 ## Conventions
 
-- Alarm names use format `{context.id}-alarm` (single) or `{context.id}-multi-alarm` (multi-dimension).
-- Period is always 60 seconds for simplicity.
+- Alarm names use format `{context.id}-alarm` (single) or `{context.id}-malarm` (multi-dimension).
+- Period defaults to 60 seconds and may be overridden independently for each alarm input.
 - Missing data defaults to `notBreaching` (safe for production).
 - SNS actions (alarm, ok, insufficient data) are all optional.
 - At least one of `metric_alarm` or `metric_alarms_by_multiple_dimensions` must be configured (enforced by check block).
@@ -121,8 +125,8 @@ No providers.
 
 | Name | Source | Version |
 | ---- | ------ | ------- |
-| <a name="module_metric_alarm"></a> [metric\_alarm](#module\_metric\_alarm) | terraform-aws-modules/cloudwatch/aws//modules/metric-alarm | 5.7.2 |
-| <a name="module_metric_alarms_by_multiple_dimensions"></a> [metric\_alarms\_by\_multiple\_dimensions](#module\_metric\_alarms\_by\_multiple\_dimensions) | terraform-aws-modules/cloudwatch/aws//modules/metric-alarms-by-multiple-dimensions | 5.7.2 |
+| <a name="module_metric_alarm"></a> [metric\_alarm](#module\_metric\_alarm) | terraform-aws-modules/cloudwatch/aws//modules/metric-alarm | 5.7.3 |
+| <a name="module_metric_alarms_by_multiple_dimensions"></a> [metric\_alarms\_by\_multiple\_dimensions](#module\_metric\_alarms\_by\_multiple\_dimensions) | terraform-aws-modules/cloudwatch/aws//modules/metric-alarms-by-multiple-dimensions | 5.7.3 |
 | <a name="module_this"></a> [this](#module\_this) | ../tags | n/a |
 
 ## Resources
@@ -168,7 +172,7 @@ No resources.
 | <a name="input_tags"></a> [tags](#input\_tags) | Additional tags (e.g. `{'BusinessUnit': 'XYZ'}`).<br/>Neither the tag keys nor the tag values will be modified by this module. | `map(string)` | `{}` | no |
 | <a name="input_terraform_source"></a> [terraform\_source](#input\_terraform\_source) | Source location to record in the Terraform\_source tag. Defaults to the caller module path when not set. | `string` | `null` | no |
 | <a name="input_tool"></a> [tool](#input\_tool) | The tool used to deploy the resource | `string` | `"Terraform"` | no |
-| <a name="input_treat_missing_data"></a> [treat\_missing\_data](#input\_treat\_missing\_data) | How to handle missing data points: 'notBreaching', 'breaching', 'missing', 'ignoreMetricTime'. | `string` | `"notBreaching"` | no |
+| <a name="input_treat_missing_data"></a> [treat\_missing\_data](#input\_treat\_missing\_data) | How to handle missing data points: 'notBreaching', 'breaching', 'missing', or 'ignore'. | `string` | `"missing"` | no |
 | <a name="input_workspace"></a> [workspace](#input\_workspace) | ID element. The Terraform workspace, to help ensure generated IDs are unique across workspaces | `string` | `null` | no |
 
 ## Outputs
diff --git a/infrastructure/modules/cloudwatch-metric-alarm/locals.tf b/infrastructure/modules/cloudwatch-metric-alarm/locals.tf
index 245bf71e..e23e770d 100644
--- a/infrastructure/modules/cloudwatch-metric-alarm/locals.tf
+++ b/infrastructure/modules/cloudwatch-metric-alarm/locals.tf
@@ -1,4 +1,27 @@
 locals {
   single_alarm_name          = format("%s-alarm", module.this.id)
-  multi_dimension_alarm_name = format("%s-multi-alarm", module.this.id)
+  multi_dimension_alarm_name = format("%s-malarm", module.this.id)
+
+  single_metric_alarm = coalesce(var.metric_alarm, {
+    metric_name         = "disabled"
+    namespace           = "disabled"
+    comparison_operator = "GreaterThanThreshold"
+    evaluation_periods  = 1
+    threshold           = 0
+    statistic           = "Sum"
+    period              = 60
+    actions_enabled     = false
+  })
+
+  multi_dimension_metric_alarm = coalesce(var.metric_alarms_by_multiple_dimensions, {
+    metric_name         = "disabled"
+    namespace           = "disabled"
+    comparison_operator = "GreaterThanThreshold"
+    evaluation_periods  = 1
+    threshold           = 0
+    statistic           = "Sum"
+    period              = 60
+    actions_enabled     = false
+    dimensions          = {}
+  })
 }
diff --git a/infrastructure/modules/cloudwatch-metric-alarm/main.tf b/infrastructure/modules/cloudwatch-metric-alarm/main.tf
index 20d43dee..a666e645 100644
--- a/infrastructure/modules/cloudwatch-metric-alarm/main.tf
+++ b/infrastructure/modules/cloudwatch-metric-alarm/main.tf
@@ -6,7 +6,7 @@
 # screening platform baseline controls:
 #
 #   * Naming: derived from context.id + alarm suffix
-#   * Period: hardcoded to 60 seconds (enforced)
+#   * Period: defaults to 60 seconds (configurable per alarm)
 #   * Statistic: defaults to Sum (configurable per-alarm)
 #   * Actions: SNS topic ARNs optional for notifications
 #   * Enabled flag: create = module.this.enabled
@@ -14,20 +14,20 @@
 
 module "metric_alarm" {
   source  = "terraform-aws-modules/cloudwatch/aws//modules/metric-alarm"
-  version = "5.7.2"
+  version = "5.7.3"
 
   create_metric_alarm = module.this.enabled && var.metric_alarm != null
 
   alarm_name          = local.single_alarm_name
-  comparison_operator = var.metric_alarm.comparison_operator
-  evaluation_periods  = var.metric_alarm.evaluation_periods
-  threshold           = var.metric_alarm.threshold
-  statistic           = var.metric_alarm.statistic
-  period              = var.metric_alarm.period
-  actions_enabled     = var.metric_alarm.actions_enabled
+  comparison_operator = local.single_metric_alarm.comparison_operator
+  evaluation_periods  = local.single_metric_alarm.evaluation_periods
+  threshold           = local.single_metric_alarm.threshold
+  statistic           = local.single_metric_alarm.statistic
+  period              = local.single_metric_alarm.period
+  actions_enabled     = local.single_metric_alarm.actions_enabled
 
-  metric_name = var.metric_alarm.metric_name
-  namespace   = var.metric_alarm.namespace
+  metric_name = local.single_metric_alarm.metric_name
+  namespace   = local.single_metric_alarm.namespace
 
   alarm_actions             = var.alarm_actions
   ok_actions                = var.ok_actions
@@ -39,21 +39,24 @@ module "metric_alarm" {
 
 module "metric_alarms_by_multiple_dimensions" {
   source  = "terraform-aws-modules/cloudwatch/aws//modules/metric-alarms-by-multiple-dimensions"
-  version = "5.7.2"
+  version = "5.7.3"
 
   create_metric_alarm = module.this.enabled && var.metric_alarms_by_multiple_dimensions != null
 
-  alarm_name          = local.multi_dimension_alarm_name
-  comparison_operator = var.metric_alarms_by_multiple_dimensions.comparison_operator
-  evaluation_periods  = var.metric_alarms_by_multiple_dimensions.evaluation_periods
-  threshold           = var.metric_alarms_by_multiple_dimensions.threshold
-  statistic           = var.metric_alarms_by_multiple_dimensions.statistic
-  period              = var.metric_alarms_by_multiple_dimensions.period
-  actions_enabled     = var.metric_alarms_by_multiple_dimensions.actions_enabled
-  dimensions          = var.metric_alarms_by_multiple_dimensions.dimensions
+  alarm_name           = local.multi_dimension_alarm_name
+  alarm_name_delimiter = "-"
+  comparison_operator  = local.multi_dimension_metric_alarm.comparison_operator
+  evaluation_periods   = local.multi_dimension_metric_alarm.evaluation_periods
+  threshold            = local.multi_dimension_metric_alarm.threshold
+  statistic            = local.multi_dimension_metric_alarm.statistic
+  period               = local.multi_dimension_metric_alarm.period
+  actions_enabled      = local.multi_dimension_metric_alarm.actions_enabled
+  dimensions = {
+    default = local.multi_dimension_metric_alarm.dimensions
+  }
 
-  metric_name = var.metric_alarms_by_multiple_dimensions.metric_name
-  namespace   = var.metric_alarms_by_multiple_dimensions.namespace
+  metric_name = local.multi_dimension_metric_alarm.metric_name
+  namespace   = local.multi_dimension_metric_alarm.namespace
 
   alarm_actions             = var.alarm_actions
   ok_actions                = var.ok_actions
diff --git a/infrastructure/modules/cloudwatch-metric-alarm/tests/cloudwatch_metric_alarm.tftest.hcl b/infrastructure/modules/cloudwatch-metric-alarm/tests/cloudwatch_metric_alarm.tftest.hcl
new file mode 100644
index 00000000..ca6f2297
--- /dev/null
+++ b/infrastructure/modules/cloudwatch-metric-alarm/tests/cloudwatch_metric_alarm.tftest.hcl
@@ -0,0 +1,176 @@
+mock_provider "aws" {
+  mock_data "aws_caller_identity" {
+    defaults = {
+      account_id = "111111111111"
+      arn        = "arn:aws:iam::111111111111:role/mock"
+      user_id    = "AIDAMOCK"
+    }
+  }
+
+  mock_data "aws_iam_session_context" {
+    defaults = {
+      issuer_arn = "arn:aws:iam::111111111111:role/mock"
+    }
+  }
+
+  mock_data "aws_iam_policy_document" {
+    defaults = {
+      json = "{\"Version\":\"2012-10-17\",\"Statement\":[]}"
+    }
+  }
+}
+
+variables {
+  service     = "bcss"
+  project     = "bcss"
+  environment = "test"
+  stack       = "account"
+  name        = "oracle-licence"
+  label_order = ["service", "environment", "stack", "workspace", "name", "attributes"]
+}
+
+run "single_metric_alarm_only" {
+  command = apply
+
+  variables {
+    metric_alarm = {
+      metric_name         = "ExampleMetric"
+      namespace           = "Example/Tests"
+      comparison_operator = "GreaterThanThreshold"
+      evaluation_periods  = 1
+      threshold           = 1
+    }
+  }
+
+  assert {
+    condition     = output.cloudwatch_metric_alarm_id != null
+    error_message = "A configured single metric alarm must return its alarm ID."
+  }
+
+  assert {
+    condition     = output.cloudwatch_metric_alarms_by_multiple_dimensions_ids == {}
+    error_message = "The unused multi-dimension alarm output must stay empty when only a single alarm is configured."
+  }
+
+  assert {
+    condition     = local.single_metric_alarm.period == 60 && local.single_metric_alarm.actions_enabled
+    error_message = "A single metric alarm must default to a 60-second period with actions enabled."
+  }
+
+  assert {
+    condition     = var.treat_missing_data == "missing"
+    error_message = "Missing data must default to missing when no value is supplied."
+  }
+}
+
+run "multi_dimension_alarm_only" {
+  command = apply
+
+  variables {
+    metric_alarms_by_multiple_dimensions = {
+      metric_name         = "ExampleMetric"
+      namespace           = "Example/Tests"
+      comparison_operator = "GreaterThanThreshold"
+      evaluation_periods  = 1
+      threshold           = 1
+      dimensions          = { Family = "integration" }
+    }
+  }
+
+  assert {
+    condition     = length(output.cloudwatch_metric_alarms_by_multiple_dimensions_ids) == 1
+    error_message = "A configured multi-dimension alarm must return one alarm ID."
+  }
+
+  assert {
+    condition     = output.cloudwatch_metric_alarm_id == null
+    error_message = "The unused single-alarm output must stay null when only a multi-dimension alarm is configured."
+  }
+
+  assert {
+    condition     = local.multi_dimension_metric_alarm.period == 60 && local.multi_dimension_metric_alarm.dimensions["Family"] == "integration"
+    error_message = "A multi-dimension alarm must preserve its dimensions and default to a 60-second period."
+  }
+}
+
+run "both_alarm_types_allow_custom_periods_and_disabled_actions" {
+  command = plan
+
+  variables {
+    metric_alarm = {
+      metric_name         = "ShortWindowMetric"
+      namespace           = "Example/Tests"
+      comparison_operator = "GreaterThanThreshold"
+      evaluation_periods  = 1
+      threshold           = 1
+      period              = 300
+      actions_enabled     = false
+    }
+
+    metric_alarms_by_multiple_dimensions = {
+      metric_name         = "HourlyMetric"
+      namespace           = "Example/Tests"
+      comparison_operator = "GreaterThanOrEqualToThreshold"
+      evaluation_periods  = 1
+      threshold           = 80
+      period              = 3600
+      actions_enabled     = false
+      dimensions          = { Family = "integration" }
+    }
+  }
+
+  assert {
+    condition = (
+      var.metric_alarm != null &&
+      var.metric_alarms_by_multiple_dimensions != null &&
+      local.single_metric_alarm.period == 300 &&
+      !local.single_metric_alarm.actions_enabled &&
+      local.multi_dimension_metric_alarm.period == 3600 &&
+      !local.multi_dimension_metric_alarm.actions_enabled
+    )
+    error_message = "Both alarm inputs must support independent periods and disabled actions."
+  }
+}
+
+run "ignore_missing_data_value_is_accepted" {
+  command = plan
+
+  variables {
+    metric_alarm = {
+      metric_name         = "ExampleMetric"
+      namespace           = "Example/Tests"
+      comparison_operator = "GreaterThanThreshold"
+      evaluation_periods  = 1
+      threshold           = 1
+    }
+    treat_missing_data = "ignore"
+  }
+
+  assert {
+    condition     = var.treat_missing_data == "ignore"
+    error_message = "The CloudWatch-supported ignore value must be accepted for missing data."
+  }
+}
+
+run "invalid_missing_data_value_is_rejected" {
+  command = plan
+
+  variables {
+    metric_alarm = {
+      metric_name         = "ExampleMetric"
+      namespace           = "Example/Tests"
+      comparison_operator = "GreaterThanThreshold"
+      evaluation_periods  = 1
+      threshold           = 1
+    }
+    treat_missing_data = "ignoreMetricTime"
+  }
+
+  expect_failures = [var.treat_missing_data]
+}
+
+run "at_least_one_alarm_configuration_is_required" {
+  command = plan
+
+  expect_failures = [check.at_least_one_alarm_configured]
+}
diff --git a/infrastructure/modules/cloudwatch-metric-alarm/variables.tf b/infrastructure/modules/cloudwatch-metric-alarm/variables.tf
index 3bb2285d..6f1f3a83 100644
--- a/infrastructure/modules/cloudwatch-metric-alarm/variables.tf
+++ b/infrastructure/modules/cloudwatch-metric-alarm/variables.tf
@@ -77,11 +77,11 @@ variable "insufficient_data_actions" {
 
 variable "treat_missing_data" {
   type        = string
-  default     = "notBreaching"
-  description = "How to handle missing data points: 'notBreaching', 'breaching', 'missing', 'ignoreMetricTime'."
+  default     = "missing"
+  description = "How to handle missing data points: 'notBreaching', 'breaching', 'missing', or 'ignore'."
 
   validation {
-    condition     = contains(["notBreaching", "breaching", "missing", "ignoreMetricTime"], var.treat_missing_data)
-    error_message = "treat_missing_data must be one of: notBreaching, breaching, missing, ignoreMetricTime."
+    condition     = contains(["notBreaching", "breaching", "missing", "ignore"], var.treat_missing_data)
+    error_message = "treat_missing_data must be one of: notBreaching, breaching, missing, ignore."
   }
 }