Formal to Client
Workplace · Greeting
You
今後担当させていただきます。どうぞよろしくお願いいたします。
こんごたんとうさせていただきます。どうぞよろしくおねがいいたします。
I will be your point of contact going forward. I look forward to working with you.
Romaji: Kongo tantō sasete itadakimasu. Dōzo yoroshiku onegai itashimasu. / Reply Romaji: Kochira koso, yoroshiku onegaishimasu.
Reply
こちらこそ、よろしくお願いします。
こちらこそ、よろしくおねがいします。
Likewise, I'm looking forward to working with you.
Gesture & etiquette
Present your business card with both hands and a bow as you say this; make warm, professional eye contact; the first meeting tone you set will define the entire client relationship.
Presenting your business card simultaneously with this phrase establishes identity in one smooth, professional gesture. '担当させていただく' (humbly serve as the person in charge) frames the role as service to the client, not authority over them — a crucial nuance that immediately builds rapport in Japanese client relationships.