While writing a formal letter to my boss, I use the phrase 'yours faithfully' to end the letter. But what should I write instead of that in the following cases:
1. While writing a formal letter to the manager of a bank or shop where I am a customer?
2. While writing a formal letter to may client?
In AmE, the following are standard/acceptable complimentary closings used in business letters:
Sincerely,
Sincerely yours,
Very truly yours,
Regards,
Best regards,
Respectfully,
Cordially,
"Yours faithfully" is very rarely used as a complimentary closing in business correspondence in the US. If you are writing to a bank or shop where you are a customer, I would suggest "sincerely", "best regards" or "respectfully". If you are writing to a long-time client with whom you have a personal relationship "faithfully yours" might be acceptable; otherwise, "very truly yours", "cordially" or "sincerely yours" are appropriate choices.
Context is always important; labelling is rarely important.