旧姓

1. Origins, structure, and basic meaning

• Structure: 旧姓 (きゅうせい) is a surname used before a change to one's current surname.
• Basic usage: It may be requested on a form or retained professionally in 旧姓を使う after the legal or personal change.

2. Common pitfalls and similar expressions

• A previously used surname
  • It often refers to a premarital surname, but more broadly it is a surname used before the current one.