Well i've just left my place of work after 7 years

Really all you need to say is that you wish to resign from your position within the company.

Ask personell or your line manager to confirm your final day of employment (normally 1 month from day of serving notice unless you agree to leave early/later, etc)

Ask them to confirm about final payments of any wages, time in lieu, holiday, etc that may be due to you.

Also ask them to confirm that your P45 will be made available on your last day of employment or before, as some companies take pleasure in forwarding these on late if you chose to leave (as i have found before )