diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index 72bccc3..4c93c35 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -32,3 +32,10 @@ jobs:
           # Token with contents + pull-requests write on sumup/homebrew-cli.
           # GITHUB_TOKEN cannot push cask updates to a different repository.
           HOMEBREW_TAP_GITHUB_TOKEN: ${{ secrets.HOMEBREW_TAP_GITHUB_TOKEN }}
+          # Apple Developer ID + notary credentials.
+          # Required for Gatekeeper-clean Homebrew installs on macOS.
+          MACOS_SIGN_P12: ${{ secrets.MACOS_SIGN_P12 }}
+          MACOS_SIGN_PASSWORD: ${{ secrets.MACOS_SIGN_PASSWORD }}
+          MACOS_NOTARY_KEY: ${{ secrets.MACOS_NOTARY_KEY }}
+          MACOS_NOTARY_KEY_ID: ${{ secrets.MACOS_NOTARY_KEY_ID }}
+          MACOS_NOTARY_ISSUER_ID: ${{ secrets.MACOS_NOTARY_ISSUER_ID }}
diff --git a/.goreleaser.yml b/.goreleaser.yml
index 79ff8cd..62d7c95 100644
--- a/.goreleaser.yml
+++ b/.goreleaser.yml
@@ -57,16 +57,6 @@ builds:
     ldflags:
       - -s -w -X github.com/sumup/sumup-cli/internal/buildinfo.Version={{ .Version }} -X github.com/sumup/sumup-cli/internal/buildinfo.Commit={{ .Commit }} -X github.com/sumup/sumup-cli/internal/buildinfo.Date={{ .Date }}
 
-    # Enable when signing credentials are configured in CI.
-    # hooks:
-    #   post:
-    #     - cmd: >-
-    #         {{ if eq .Os "darwin" }}./scripts/sign-macos.sh '{{ .Path }}'{{ else }}echo{{ end }}
-    #       output: true
-    #     - cmd: >-
-    #         {{ if eq .Os "windows" }}pwsh ./scripts/sign-windows.ps1 '{{ .Path }}'{{ else }}echo{{ end }}
-    #       output: true
-
 archives:
   - id: linux-archive
     ids: [linux]
@@ -105,6 +95,20 @@ archives:
 checksum:
   name_template: checksums.txt
 
+# Sign and notarize macOS binaries when Apple credentials are present.
+# Homebrew installs require notarized binaries (no quarantine bypass in the cask).
+notarize:
+  macos:
+    - enabled: '{{ isEnvSet "MACOS_SIGN_P12" }}'
+      ids: [macos]
+      sign:
+        certificate: "{{ .Env.MACOS_SIGN_P12 }}"
+        password: "{{ .Env.MACOS_SIGN_PASSWORD }}"
+      notarize:
+        issuer_id: "{{ .Env.MACOS_NOTARY_ISSUER_ID }}"
+        key_id: "{{ .Env.MACOS_NOTARY_KEY_ID }}"
+        key: "{{ .Env.MACOS_NOTARY_KEY }}"
+
 # Publishes Casks/sumup.rb to the public tap sumup/homebrew-cli.
 # Requires HOMEBREW_TAP_GITHUB_TOKEN with write access to that repository.
 homebrew_casks:
@@ -122,14 +126,6 @@ homebrew_casks:
     homepage: https://developer.sumup.com
     description: Command line tool for interacting with SumUp APIs.
     license: Apache-2.0
-    # Binaries are not yet notarized; clear quarantine so Gatekeeper does not
-    # block the unsigned CLI. Remove this hook once macOS signing is enabled.
-    hooks:
-      post:
-        install: |
-          if OS.mac?
-            system_command "/usr/bin/xattr", args: ["-dr", "com.apple.quarantine", "#{staged_path}/sumup"]
-          end
     skip_upload: auto
 
 changelog:
diff --git a/scripts/sign-macos.sh b/scripts/sign-macos.sh
index bb21267..e290500 100755
--- a/scripts/sign-macos.sh
+++ b/scripts/sign-macos.sh
@@ -1,4 +1,6 @@
 #!/usr/bin/env bash
+# Local helper for macOS signing. Release builds use GoReleaser's notarize
+# section with MACOS_SIGN_P12 / MACOS_SIGN_PASSWORD / MACOS_NOTARY_* secrets.
 set -euo pipefail
 
 binary_path="${1:-}"
@@ -7,18 +9,13 @@ if [[ -z "$binary_path" ]]; then
   exit 1
 fi
 
-# Placeholder script for future macOS signing and notarization.
-# Expected env vars once enabled:
-# - APPLE_CERT_BASE64
-# - APPLE_CERT_PASSWORD
-# - APPLE_TEAM_ID
-# - APPLE_ID
-# - APPLE_APP_SPECIFIC_PASSWORD
-#
-# Example (to enable later):
-# security create-keychain -p "$KEYCHAIN_PASSWORD" build.keychain
-# echo "$APPLE_CERT_BASE64" | base64 --decode > cert.p12
-# security import cert.p12 -k build.keychain -P "$APPLE_CERT_PASSWORD" -T /usr/bin/codesign
-# codesign --force --timestamp --options runtime --sign "Developer ID Application: ..." "$binary_path"
+if [[ -z "${MACOS_SIGN_IDENTITY:-}" ]]; then
+  echo "MACOS_SIGN_IDENTITY is not set; skipping codesign for $binary_path" >&2
+  exit 0
+fi
+
+codesign --force --timestamp --options runtime \
+  --sign "$MACOS_SIGN_IDENTITY" \
+  "$binary_path"
 
-echo "macOS signing is currently disabled. Skipping: $binary_path"
+echo "Signed $binary_path with $MACOS_SIGN_IDENTITY"
diff --git a/scripts/sign-windows.ps1 b/scripts/sign-windows.ps1
index 9afa5a4..e03a17f 100644
--- a/scripts/sign-windows.ps1
+++ b/scripts/sign-windows.ps1
@@ -5,13 +5,56 @@ param(
 
 $ErrorActionPreference = "Stop"
 
-# Placeholder script for future Windows Authenticode signing.
-# Expected env vars once enabled:
-# - WINDOWS_CERT_BASE64
-# - WINDOWS_CERT_PASSWORD
-#
-# Example (to enable later):
-# [IO.File]::WriteAllBytes("cert.pfx", [Convert]::FromBase64String($env:WINDOWS_CERT_BASE64))
-# signtool sign /f cert.pfx /p $env:WINDOWS_CERT_PASSWORD /fd SHA256 /tr http://timestamp.digicert.com /td SHA256 $BinaryPath
+# Cross-compiled Windows binaries are signed only when this hook runs on Windows
+# with Authenticode credentials available.
+if (-not $IsWindows) {
+  Write-Output "Not running on Windows; skipping Authenticode signing for $BinaryPath"
+  exit 0
+}
 
-Write-Output "Windows signing is currently disabled. Skipping: $BinaryPath"
+if (-not $env:WINDOWS_CERT_BASE64 -or -not $env:WINDOWS_CERT_PASSWORD) {
+  Write-Output "WINDOWS_CERT_BASE64 / WINDOWS_CERT_PASSWORD not set; skipping Authenticode signing for $BinaryPath"
+  exit 0
+}
+
+$certPath = Join-Path ([System.IO.Path]::GetTempPath()) ("sumup-windows-" + [guid]::NewGuid().ToString() + ".pfx")
+try {
+  [IO.File]::WriteAllBytes($certPath, [Convert]::FromBase64String($env:WINDOWS_CERT_BASE64))
+
+  $signtool = $null
+  $candidates = @(
+    "${env:ProgramFiles(x86)}\Windows Kits\10\bin\*\x64\signtool.exe",
+    "${env:ProgramFiles}\Windows Kits\10\bin\*\x64\signtool.exe"
+  )
+  foreach ($pattern in $candidates) {
+    $match = Get-Item $pattern -ErrorAction SilentlyContinue | Sort-Object FullName -Descending | Select-Object -First 1
+    if ($match) {
+      $signtool = $match.FullName
+      break
+    }
+  }
+  if (-not $signtool) {
+    $signtool = Get-Command signtool.exe -ErrorAction SilentlyContinue | Select-Object -ExpandProperty Source
+  }
+  if (-not $signtool) {
+    throw "signtool.exe not found; install Windows SDK signing tools"
+  }
+
+  & $signtool sign `
+    /f $certPath `
+    /p $env:WINDOWS_CERT_PASSWORD `
+    /fd SHA256 `
+    /tr http://timestamp.digicert.com `
+    /td SHA256 `
+    $BinaryPath
+  if ($LASTEXITCODE -ne 0) {
+    throw "signtool failed with exit code $LASTEXITCODE"
+  }
+
+  Write-Output "Signed $BinaryPath"
+}
+finally {
+  if (Test-Path $certPath) {
+    Remove-Item -Force $certPath
+  }
+}