"Covering letter" vs "cover letter"

word-choice phrases word-usage business-language

According to ODO, covering letter is used in UK English, and cover letter in US English. They mean the exact same thing.

According to Google Ngram, since the 1980s, covering letter is in a steady decline, while cover letter has become the most popular one.

Google Ngram

According to Google Trends, cover letter is the most popular one.

Google Trends

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