源泉徴収 計算チェック 10.21%・20.42%（令和9年改正対応） — Licence

Free scope
  開いているファイル1本の源泉徴収コードを9規則で検査し、行番号と正しい式を表示（キー不要） is free for any use, personal or commercial, for as long as you keep the
  extension installed, and the online check at the product page is free without registration.

Paid scope
  ワークスペース全体の一括検査と、指摘をCSV（ファイル・行・規則・正しい式）で書き出して税理士・レビューに渡す is the paid part. It asks for a licence key issued at purchase (one seat, one key). The key is checked against the payment provider and
  cached locally for 30 days so it keeps working offline.

Redistribution
  You may not resell, re-host or bundle this extension or its rule set. The rule set and the
  engine are provided as-is; check results are advisory and do not constitute legal advice.

(c) ReadyStack — https://getreadystack.com
