it has been decided that

ことになる reports an arrangement or decision made by others or by circumstances, not by the speaker's own will. It is also used to soften decisions you did in fact make. The state ことになっている describes standing rules and customs.

Examples

• 四よん月がつから東京とうきょうに住すむことになりました。

  Shigatsu kara Toukyou ni sumu koto ni narimashita.

  It has been decided that I will live in Tokyo from April.

• 来週らいしゅう大阪おおさかへ出張しゅっちょうすることになりました。

  Raishuu Oosaka e shucchou suru koto ni narimashita.

  It has been arranged that I will go on a business trip to Osaka next week.

Vocabulary in these examples

• 四 four
• 月 moon; month
• 住む to live; to reside
• なる to become
• 来週 next week
• 出張 business trip

Related patterns · Nominalizers and decisions

• 〜ことにする to decide to do
• 〜の（名詞化） the act of doing (nominalizer)