diff --git a/.github/workflows/gem-bump-checker.yml b/.github/workflows/gem-bump-checker.yml
new file mode 100644
index 000000000..152a846ee
--- /dev/null
+++ b/.github/workflows/gem-bump-checker.yml
@@ -0,0 +1,105 @@
+name: Gem Bump Checker
+
+on:
+  workflow_call:
+    inputs:
+      gem_name:
+        required: false
+        type: string
+        default: ${{ github.event.repository.name }}
+    secrets:
+      GH_TOKEN:
+        required: true
+
+jobs:
+  check-files:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        show-progress: false
+        token: ${{ secrets.GH_TOKEN }}
+    - uses: ruby/setup-ruby@v1
+      with:
+        rubygems: latest
+        bundler-cache: true
+
+    - name: "Determine HEAD of default branch"
+      id: fetch_default_branch_head
+      run: echo "sha=$(git ls-remote origin HEAD | cut -f 1)" >> "$GITHUB_OUTPUT"
+
+    - name: "Determine HEAD of current branch"
+      id: fetch_current_branch_head
+      run: echo "sha=$(git rev-parse HEAD)" >> "$GITHUB_OUTPUT"
+
+    - name: Check PR author
+      id: check_pr_author
+      run: echo "pr_author=${{ github.event.pull_request.user.login }}" >> "$GITHUB_OUTPUT"
+
+    - name: Check for version and changelog updates
+      if: steps.check_pr_author.outputs.pr_author != 'dependabot[bot]'
+      env:
+        GH_TOKEN: ${{ secrets.GH_TOKEN }}
+        BASE_REF: ${{ steps.fetch_default_branch_head.outputs.sha }}
+        HEAD_REF: ${{ steps.fetch_current_branch_head.outputs.sha }}
+      run: |
+        MODIFIED_FILES=$(git diff --name-only "$BASE_REF".."$HEAD_REF")
+
+        if ! echo "$MODIFIED_FILES" | grep 'version.rb' && \
+           ! echo "$MODIFIED_FILES" | grep '\.gemspec$'; then
+          echo "Error: Either version.rb or a .gemspec file must be modified with each pull request to bump the gem version."
+          exit 1
+        fi
+
+        if ! echo "$MODIFIED_FILES" | grep 'CHANGELOG.md'; then
+          echo "Error: CHANGELOG.md must be updated with each pull request."
+          exit 1
+        fi
+
+    - name: Dependabot version bump
+      if: steps.check_pr_author.outputs.pr_author == 'dependabot[bot]'
+      env:
+        GEM_NAME: ${{ inputs.gem_name }}
+        GH_TOKEN: ${{ secrets.GH_TOKEN }}
+        BRANCH_NAME: ${{ github.event.pull_request.head.ref }}
+      run: |
+        set -euo pipefail
+
+        git checkout "$BRANCH_NAME"
+
+        curr_ver=$(ruby -r rubygems -e "puts Gem::Specification::load('$GEM_NAME.gemspec').version")
+        major=$(echo "$curr_ver" | cut -d . -f1)
+        minor=$(echo "$curr_ver" | cut -d . -f2)
+        patch=$(echo "$curr_ver" | cut -d . -f3)
+        next_ver="$major.$minor.$((patch + 1))" # Increment the patch version
+
+        if ! [[ -r CHANGELOG.md ]]; then
+          echo "CHANGELOG.md not found or not readable. Exiting."
+          exit 0
+        fi
+
+        if ! grep -qR --include "version.rb" --include "*.gemspec" "$curr_ver"; then
+          echo "Can't find version.rb or *.gemspec containing the string '$curr_ver'. Exiting."
+          exit 0
+        fi
+
+        find . -type f \( -iname "version.rb" -o -iname "*.gemspec" \) -exec sed -i "0,/$curr_ver/s//${next_ver}/" {} \;
+
+        printf "# %s\n\n* Update dependencies\n\n" "$next_ver" > NEW_CHANGELOG.md
+        cat CHANGELOG.md >> NEW_CHANGELOG.md
+        mv NEW_CHANGELOG.md CHANGELOG.md
+
+        git config --global user.name "GOV.UK Continuous Integration User"
+        git config --global user.email "govuk-ci@users.noreply.github.com"
+
+        git add CHANGELOG.md
+
+        find . \( -path ./vendor/bundle -prune \) -o \( -type f \( -iname version.rb -o -iname "*.gemspec" \) -print \) | while read -r file; do
+          file_path=${file#./}
+          git add "$file_path"
+        done
+
+        git commit -m "Automated version bump to v$next_ver"
+        git push origin "$BRANCH_NAME"