diff --git a/README.md b/README.md
index 5256248624..7b384acd8a 100644
--- a/README.md
+++ b/README.md
@@ -53,6 +53,23 @@ These 2 layers are meant to be used in conjunction to instrument your lambda fun
 
 To get a better understanding of the proposed design for the OpenTelemetry Lambda extension, you can see the [Design Proposal here.](docs/design_proposal.md)
 
+## Wrapper Script Configuration
+
+Each language layer includes a wrapper script (`otel-handler` or `otel-instrument`) that is invoked via `AWS_LAMBDA_EXEC_WRAPPER` before the Lambda runtime starts. These scripts configure the following environment variables:
+
+### `OTEL_PROPAGATORS`
+
+If not already set, the wrapper scripts default `OTEL_PROPAGATORS` to `tracecontext,baggage,xray`.
+
+### `OTEL_RESOURCE_ATTRIBUTES`
+
+The wrapper scripts extend `OTEL_RESOURCE_ATTRIBUTES` with:
+
+- **`service.name`** — set to the Lambda function name (`AWS_LAMBDA_FUNCTION_NAME`) if not already present.
+- **`cloud.account.id`** — the AWS account ID, read from a symlink at `/tmp/.otel-aws-account-id` that is created by the collector extension during registration. This is added automatically when the collector layer is used alongside a language layer. If the symlink does not exist (e.g., when running without the collector layer), the attribute is silently skipped.
+
+User-provided values in `OTEL_RESOURCE_ATTRIBUTES` are never overwritten.
+
 ## Features
 
 The following is a list of features provided by the OpenTelemetry layers.
diff --git a/java/layer-javaagent/scripts/otel-handler b/java/layer-javaagent/scripts/otel-handler
index adb31a263e..08cd69a747 100755
--- a/java/layer-javaagent/scripts/otel-handler
+++ b/java/layer-javaagent/scripts/otel-handler
@@ -8,6 +8,11 @@ if [[ $OTEL_RESOURCE_ATTRIBUTES != *"service.name="* ]]; then
   export OTEL_RESOURCE_ATTRIBUTES="service.name=${AWS_LAMBDA_FUNCTION_NAME},${OTEL_RESOURCE_ATTRIBUTES}"
 fi
 
+CLOUD_ACCOUNT_ID=$(readlink /tmp/.otel-aws-account-id 2>/dev/null || true)
+if [[ -n "$CLOUD_ACCOUNT_ID" && $OTEL_RESOURCE_ATTRIBUTES != *"cloud.account.id="* ]]; then
+  export OTEL_RESOURCE_ATTRIBUTES="cloud.account.id=${CLOUD_ACCOUNT_ID},${OTEL_RESOURCE_ATTRIBUTES}"
+fi
+
 if [[ -z "$OTEL_PROPAGATORS" ]]; then
   export OTEL_PROPAGATORS="tracecontext,baggage,xray"
 fi
diff --git a/java/layer-wrapper/scripts/otel-handler b/java/layer-wrapper/scripts/otel-handler
index 0bc9d33dd6..155eaef865 100755
--- a/java/layer-wrapper/scripts/otel-handler
+++ b/java/layer-wrapper/scripts/otel-handler
@@ -9,6 +9,11 @@ if [[ $OTEL_RESOURCE_ATTRIBUTES != *"service.name="* ]]; then
   export OTEL_RESOURCE_ATTRIBUTES="service.name=${AWS_LAMBDA_FUNCTION_NAME},${OTEL_RESOURCE_ATTRIBUTES}"
 fi
 
+CLOUD_ACCOUNT_ID=$(readlink /tmp/.otel-aws-account-id 2>/dev/null || true)
+if [[ -n "$CLOUD_ACCOUNT_ID" && $OTEL_RESOURCE_ATTRIBUTES != *"cloud.account.id="* ]]; then
+  export OTEL_RESOURCE_ATTRIBUTES="cloud.account.id=${CLOUD_ACCOUNT_ID},${OTEL_RESOURCE_ATTRIBUTES}"
+fi
+
 if [[ -z "$OTEL_PROPAGATORS" ]]; then
   export OTEL_PROPAGATORS="tracecontext,baggage,xray"
 fi
diff --git a/nodejs/packages/layer/scripts/otel-handler b/nodejs/packages/layer/scripts/otel-handler
index b3c615e6d3..32e612a1a6 100755
--- a/nodejs/packages/layer/scripts/otel-handler
+++ b/nodejs/packages/layer/scripts/otel-handler
@@ -12,6 +12,11 @@ if [[ $OTEL_RESOURCE_ATTRIBUTES != *"service.name="* ]]; then
   fi
 fi
 
+CLOUD_ACCOUNT_ID=$(readlink /tmp/.otel-aws-account-id 2>/dev/null || true)
+if [[ -n "$CLOUD_ACCOUNT_ID" && $OTEL_RESOURCE_ATTRIBUTES != *"cloud.account.id="* ]]; then
+  export OTEL_RESOURCE_ATTRIBUTES="cloud.account.id=${CLOUD_ACCOUNT_ID},${OTEL_RESOURCE_ATTRIBUTES}"
+fi
+
 if [[ -z "$OTEL_PROPAGATORS" ]]; then
   export OTEL_PROPAGATORS="tracecontext,baggage,xray"
 fi
diff --git a/python/src/otel/otel_sdk/otel-instrument b/python/src/otel/otel_sdk/otel-instrument
index 9d89c96b62..90df003d30 100755
--- a/python/src/otel/otel_sdk/otel-instrument
+++ b/python/src/otel/otel_sdk/otel-instrument
@@ -146,6 +146,14 @@ else
     export OTEL_RESOURCE_ATTRIBUTES="$LAMBDA_RESOURCE_ATTRIBUTES,$OTEL_RESOURCE_ATTRIBUTES";
 fi
 
+CLOUD_ACCOUNT_ID=$(readlink /tmp/.otel-aws-account-id 2>/dev/null || true)
+if [ -n "$CLOUD_ACCOUNT_ID" ]; then
+  case "$OTEL_RESOURCE_ATTRIBUTES" in
+    *cloud.account.id=*) ;;
+    *) export OTEL_RESOURCE_ATTRIBUTES="cloud.account.id=${CLOUD_ACCOUNT_ID},${OTEL_RESOURCE_ATTRIBUTES}" ;;
+  esac
+fi
+
 
 # - Uses the default `OTEL_PROPAGATORS` which is set to `tracecontext,baggage`
 
diff --git a/ruby/src/otel/layer/otel-handler b/ruby/src/otel/layer/otel-handler
index a7994f48ed..87ae1811af 100755
--- a/ruby/src/otel/layer/otel-handler
+++ b/ruby/src/otel/layer/otel-handler
@@ -19,4 +19,12 @@ else
     export OTEL_RESOURCE_ATTRIBUTES="$LAMBDA_RESOURCE_ATTRIBUTES,$OTEL_RESOURCE_ATTRIBUTES";
 fi
 
+CLOUD_ACCOUNT_ID=$(readlink /tmp/.otel-aws-account-id 2>/dev/null || true)
+if [ -n "$CLOUD_ACCOUNT_ID" ]; then
+  case "$OTEL_RESOURCE_ATTRIBUTES" in
+    *cloud.account.id=*) ;;
+    *) export OTEL_RESOURCE_ATTRIBUTES="cloud.account.id=${CLOUD_ACCOUNT_ID},${OTEL_RESOURCE_ATTRIBUTES}" ;;
+  esac
+fi
+
 exec "$@"