邀請信包括宴會、舞會、晚餐、聚會、婚禮等各種邀請信件，形式上大體分為兩種:一種為正規的格式 (formal correspondence)，亦稱請柬;一種是非正式格式 (informal correspondence), 即一般的邀請信。邀請信是在形式上不如請柬那樣正規，但也是很考究。書寫時應注意:

　　邀請信一定要將邀請的時間(年、月、日、鐘點)、地點、場合寫清楚，不能使接信人存在任何疑慮。例如:“I’d like you and Bob to come to Luncheon next Friday.”這句話中所指的是哪個星期五并不明確，所以應加上具體日期, “I’d like you and Bob to come to luncheon next Friday, May the fifth.”

　　1. 邀請朋友共進午餐 Inviting a friend to informal luncheon

　　Dear [Zhang Ying]:

　　Will you come to luncheon on [Friday, May the fifth], at [twelve o’clock]?

　　My niece [Mary] is visiting us and I think you will enjoy meeting her. She is a charming, very pretty girl … and very good company! [John and Jane] will be here, and perhaps we can [give a dance] after luncheon. Do say you’ll come!

　　Affectionately yours,

　　Li Ming

　　親愛的[張營]:

　　您能在[5月5日星期五中午12點鐘] 來吃午飯嗎?

　　我侄女[瑪麗]正在我們家中作客，我想您會樂于見到她的。她是個漂亮而聰明的女孩子，……同她在一起是很使人高興的![約翰和簡]也到這里來，也許在飯后我們能[開個舞會]，說好，一定得來呀!

　　2. 邀請朋友同他們不認識的人一起共進晚餐 Inviting friends to supper with the strangers

　　Dear [Susan]:

　　I know you are interested in [oil painting], so I’m sure you’ll be interested in [Mr. and Mrs. Lin dun]! They are coming here to supper [next Sunday night, October the twelfth], and we’d like you and [Walter] to come, too.

　　[Mr. and Mrs. Lin Dun] are that very charming couple we met in [London] last summer. They have a wonderful collection of [oil paintings of various stages]; and I understand that Mr. Lin Dun is quite an authority on [oil painting]. I’m sure you and Walter will thoroughly enjoy and evening in their company.

　　We’re planning supper at six; that will give us a nice long evening to talk. If I don’t hear from you before then, I’ll be expecting you on the [twelfth]!

　　Affectionately yours,

　　Li Ming

　　親愛的[蘇珊]:

　　我知道您對[油畫]是有興趣的，所以我相信您對林頓夫婦也會感興趣。他們將在[10月12日(下星期日)]來吃飯，我們很希望您和瓦爾特也能同來。

　　[林頓夫婦]是那么好的一對夫妻。我們是去年夏天在[倫敦]認識的。他們集有[各個不同時期精美的油畫作品]。我知道，林頓先生在研究[油畫]方面是頗有權威的。我深信，那天晚上您和瓦爾特同他們在一起，一定會很愉快。

　　我們準備在6點鐘吃晚飯，這樣就能有較長的時間閑談。如果事前接不到您的回信，我就指望你們那天到來。