Is IBAN the same as Account Number? My salary was not transferred as I supplied only an account number and swift code, they said they need the IBAN number.

I believe the IBAN no. Is a number belonging to the bank used in wiring money between banks, particularly internationally.  Does your pay come from another country than the one in which you are resident by any chance?

If the IBAN number does not appear on your bank statement you need to ring your bank to find out what it is.

It certainly does not apply to your account, but is really an international sorting code for the bank.