merge workbooks

I recieve a spreadsheet daily with these headings:
Region Branch # Account # date worked notes

the next day i recieve a new sheet that includes the previous accounts and some new ones. i want to combine the 2 sheets so that the date worked column and notes column will run from day to day. the account number is unique so with my limited programming skills i thought

IF account # is duplicate THEN update date worked and notes, IF account # is not duplicate THEN update all columns.

would work but obviously not since excel is not html. please advise as i am simply copy/paste the old sheet to the new and sorting by account number and manually deleting dup rows. this is becoming too time consuming as the number of accounts grows.

i assume you mean autofilter the date worked column. that would allow me to see what was worked when but I would still (over a week period) 5 instances of the same account with notes for each day. i only want 1 instance of each account with 1 set of notes.

if i am understanding what you mean by filter incorrectly, i apologize. i have much to learn

i found a command called vlookup...using this i was able to reference the account # from the new worksheet and relate it to the account # from the previous days sheet. i used the notes column as the output value. so when vlookup finds a matching account # it transfers the notes over to the new sheet.