6.2 Outgoing letters. Remember the basic pairs for opening and closing letters:
Dear Sir/Madam ... Yours faithfully
Dear Mr/Ms/Dr Bloggs ... Yours sincerely
The tendency is towards greater use of the second, less formal, pair when the correspondent's name is known. It should certainly be used in letters of reply to individuals.
Note that commas should be placed either after both opening and closing formula, or after neither.
6.3 Letters to VIPs. Letters to ambassadors and permanent representatives. For all countries except the UK, start “Your Excellency”. For the UK, start “Sir/Madam”. For all countries close as follows.
I have the honour to be, Sir/Madam,
Yours faithfully (or just Yours faithfully)
6.4 Letters to ministers. For all countries except the UK, start “Sir/Madam” and close:
I have the honour to be, Sir/Madam,
Yours faithfully (or just Yours faithfully)
For the UK, start “Sir/Madam/My Lord” and close:
I remain (or I am), Sir/Madam/My Lord,
Yours faithfully (or just Yours faithfully)
6.5 Letters to presidents of EU institutions. Start “Sir/Madam,” and close:
I have the honour to be, Sir/Madam,
Yours faithfully
6.6 Agreements in the form of an exchange of letters.
Letter 1
Start:
Sir/Your Excellency,
I have the honour ...
Close:
I should be obliged if you would inform me whether/confirm that your Government is in agreement with the above.
Please accept, Sir/Your Excellency, the assurance of my highest consideration.
Letter 2
Start:
Sir/Your Excellency,
I have the honour to acknowledge receipt of your letter of today's date, which reads as follows:
(Insert text of letter 1)
Close:
I am able to inform you/confirm that my Government is in agreement with the contents of your letter/I have the honour to confirm that the above is acceptable to my Government and that your letter and this letter constitute an agreement in accordance with your proposal.

Please accept, Sir/Your Excellency, the assurance of my highest consideration.
6.7 Exchanges of Notes (Notes Verbales).
Start:
(Mission No 1) presents its compliments to (Mission No 2) and has the honour to refer to ...
Close:
(Mission No 1) avails itself of this opportunity to renew to (Mission No 2) the assurance of its highest consideration.