diff --git a/.github/workflows/stage-4-acceptance.yaml b/.github/workflows/stage-4-acceptance.yaml
index c6dc58e..d554f98 100644
--- a/.github/workflows/stage-4-acceptance.yaml
+++ b/.github/workflows/stage-4-acceptance.yaml
@@ -31,10 +31,6 @@ on:
         description: "Version of the software, set by the CI/CD pipeline workflow"
         required: true
         type: string
-      target_environment:
-        description: "Environment to run acceptance tests with"
-        required: true
-        type: string
 
 jobs:
   environment-set-up:
diff --git a/LICENCE.md b/LICENCE.md
index 3b8ee5f..02174c4 100644
--- a/LICENCE.md
+++ b/LICENCE.md
@@ -1,6 +1,6 @@
 # MIT Licence
 
-Copyright (c) 2026 Crown Copyright NHS England.
+Copyright (c) 2025 Crown Copyright NHS England.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/scripts/lambda-container-build/docker.sh b/scripts/lambda-container-build/docker.sh
new file mode 100755
index 0000000..b86a874
--- /dev/null
+++ b/scripts/lambda-container-build/docker.sh
@@ -0,0 +1,129 @@
+#!/bin/bash
+
+# Fail fast on errors, unset variables, and pipeline failures.
+set -euo pipefail
+
+# Ensure build.sh is executable and build the lambda artifacts before producing the Docker image.
+chmod +x ./build.sh
+./build.sh
+
+
+# Parse arguments
+BASE_IMAGE=""
+while [[ $# -gt 0 ]]; do
+  case $1 in
+    --base-image)
+      BASE_IMAGE="$2"
+      shift 2
+      ;;
+    *)
+      echo "Unknown argument: $1" >&2
+      exit 1
+      ;;
+  esac
+done
+
+if [[ -z "$BASE_IMAGE" ]]; then
+  echo "Error: --base-image parameter is required." >&2
+  exit 1
+fi
+
+CSI="${PROJECT}-${ENVIRONMENT}-${COMPONENT}"
+ECR_REPO="${ECR_REPO:-nhs-notify-main-acct}"
+GHCR_LOGIN_TOKEN="${GITHUB_TOKEN}"
+GHCR_LOGIN_USER="${GITHUB_ACTOR}"
+LAMBDA_NAME="${LAMBDA_NAME:-$(basename "$PWD")}"
+
+## Set IMAGE_TAG_SUFFIX based on git tag or short SHA for unique lambda image tagging in ECR.
+#This ensures that each build produces a uniquely identifiable image, and tagged releases are easily traceable.
+echo "Checking if current commit is a tag..."
+GIT_TAG="$(git describe --tags --exact-match 2>/dev/null || true)"
+if [ -n "$GIT_TAG" ]; then
+  TAGGED="tag-$GIT_TAG"
+  echo "On tag: $GIT_TAG, exporting IMAGE_TAG_SUFFIX as tag: $TAGGED"
+  export IMAGE_TAG_SUFFIX="$TAGGED"
+
+else
+  SHORT_SHA="sha-$(git rev-parse --short HEAD)"
+  echo "Not on a tag, exporting IMAGE_TAG_SUFFIX as short SHA: $SHORT_SHA"
+  export IMAGE_TAG_SUFFIX="$SHORT_SHA"
+fi
+
+## Check if we are running in the context of a Terraform apply or plan, and set PUBLISH_LAMBDA_IMAGE accordingly. We only want to push images to ECR on apply, not on plan.
+echo "Checking if ACTION is 'apply' to set PUBLISH_LAMBDA_IMAGE..."
+if [ "$ACTION" = "apply" ]; then
+  echo "Setting PUBLISH_LAMBDA_IMAGE to true for apply action"
+  export PUBLISH_LAMBDA_IMAGE="true"
+else
+  echo "Not setting PUBLISH_LAMBDA_IMAGE for action ($ACTION)"
+fi
+
+# Ensure required AWS/ECR configuration is present.
+echo "BASE_IMAGE: ${BASE_IMAGE:-<unset>}"
+echo "AWS_ACCOUNT_ID: ${AWS_ACCOUNT_ID:-<unset>}"
+echo "AWS_REGION: ${AWS_REGION:-<unset>}"
+echo "COMPONENT: ${COMPONENT:-<unset>}"
+echo "CSI: ${CSI:-<unset>}"
+echo "ECR_REPO: ${ECR_REPO:-<unset>}"
+echo "ENVIRONMENT: ${ENVIRONMENT:-<unset>}"
+echo "GHCR_LOGIN_TOKEN: ${GHCR_LOGIN_TOKEN:-<unset>}"
+echo "GHCR_LOGIN_USER: ${GHCR_LOGIN_USER:-<unset>}"
+echo "IMAGE_TAG_SUFFIX: ${IMAGE_TAG_SUFFIX:-<unset>}"
+echo "LAMBDA_NAME: ${LAMBDA_NAME:-<unset>}"
+
+# Authenticate Docker with AWS ECR using an ephemeral login token.
+aws ecr get-login-password --region "${AWS_REGION}" | docker login --username AWS --password-stdin "${AWS_ACCOUNT_ID}".dkr.ecr."${AWS_REGION}".amazonaws.com
+
+# Authenticate to GitHub Container Registry for base images.
+if [ -n "${GHCR_LOGIN_USER:-}" ] && [ -n "${GHCR_LOGIN_TOKEN:-}" ]; then
+  echo "Attempting GHCR login as ${GHCR_LOGIN_USER}..."
+  if echo "${GHCR_LOGIN_TOKEN}" | docker login ghcr.io --username "${GHCR_LOGIN_USER}" --password-stdin; then
+    echo "GHCR login successful."
+  else
+    echo "GHCR login failed!" >&2
+  fi
+fi
+
+# Namespace tag by CSI and lambda name to avoid cross-environment collisions.
+IMAGE_TAG="${CSI}-${LAMBDA_NAME}"
+
+# Compose the full ECR image references.
+ECR_REPO_URI="${AWS_ACCOUNT_ID}.dkr.ecr.${AWS_REGION}.amazonaws.com/${ECR_REPO}"
+
+# Final tag names we will produce
+
+IMAGE_TAG_LATEST="${ECR_REPO_URI}:${IMAGE_TAG}-latest"
+IMAGE_TAG_SUFFIXED="${ECR_REPO_URI}:${IMAGE_TAG}-${IMAGE_TAG_SUFFIX}"
+
+echo "Will build and tag images:"
+echo "  LATEST -> ${IMAGE_TAG_LATEST}"
+echo "  SUFFIXED -> ${IMAGE_TAG_SUFFIXED}"
+
+# Build and tag the Docker image for the lambda.
+# --load makes the built image available to the local docker daemon (single-platform).
+docker buildx build \
+  -f docker/lambda/Dockerfile \
+  --platform=linux/amd64 \
+  --provenance=false \
+  --sbom=false \
+  --build-arg BASE_IMAGE="${BASE_IMAGE}" \
+  -t "${IMAGE_TAG_LATEST}" \
+  -t "${IMAGE_TAG_SUFFIXED}" \
+  --load \
+  .
+
+# Push the image tag(s) to ECR on apply only. The Terraform configuration will reference image digest.
+if [ "${PUBLISH_LAMBDA_IMAGE:-false}" = "true" ]; then
+  echo "PUBLISH_LAMBDA_IMAGE is set to true. Pushing Docker images to ECR..."
+
+
+  for TAG in "${IMAGE_TAG_LATEST}" "${IMAGE_TAG_SUFFIXED}"; do
+    echo "Pushing ${TAG}..."
+    docker push "${TAG}"
+  done
+
+  echo "Push complete."
+else
+  echo "PUBLISH_LAMBDA_IMAGE is not set to true (likely TF Plan). Skipping Docker push."
+  exit 0
+fi