diff --git a/Casks/w/wiso-steuer-2021.rb b/Casks/w/wiso-steuer-2021.rb
new file mode 100644
index 0000000000000..9c02e9afdd5de
--- /dev/null
+++ b/Casks/w/wiso-steuer-2021.rb
@@ -0,0 +1,41 @@
+cask "wiso-steuer-2021" do
+  # NOTE: "2021" is not a version number, but an intrinsic part of the product name
+  version "28.16.4440-RC1"
+  sha256 "a2b4ef4bd67b53109c557684dd773e860fa287257ad023ac1388395f0aa18172"
+
+  url "https://update.buhl-data.com/Updates/Steuer/2021/Mac/Files/#{version}/SteuerMac2021-#{version.split("-").first}.dmg",
+      verified: "update.buhl-data.com/Updates/Steuer/"
+  name "WISO Steuer 2021"
+  desc "Tax declaration for the fiscal year 2020"
+  homepage "https://www.buhl.de/produkte/wiso-steuer-mac/"
+
+  livecheck do
+    url "https://update.buhl-data.com/Updates/Steuer/2021/Mac/Aktuell/appcast-steuer.xml"
+    regex(%r{/v?(\d+(?:\.\d+)+[^/]*)/SteuerMac2021[._-]v?(\d+(?:\.\d+)+)\.dmg}i)
+    strategy :sparkle do |item, regex|
+      match = item.url&.match(regex)
+      next if match.blank?
+
+      match[1]
+    end
+  end
+
+  auto_updates true
+  depends_on macos: ">= :high_sierra"
+
+  # Renamed for consistency: app name differs in Finder to shell
+  app "SteuerMac 2021.app", target: "WISO Steuer 2021.app"
+
+  zap trash: [
+    "~/Library/Application Support/BuhlData.com/WISOsteuerMac2021",
+    "~/Library/Caches/com.BuhlData.WISOsteuerMac2021",
+    "~/Library/HTTPStorages/com.BuhlData.WISOsteuerMac2021",
+    "~/Library/Preferences/com.buhldata.WISOsteuerMac2021.plist",
+    "~/Library/Saved Application State/com.BuhlData.WISOsteuerMac2021.savedState",
+    "~/Library/WebKit/com.BuhlData.WISOsteuerMac2021",
+  ]
+
+  caveats do
+    requires_rosetta
+  end
+end