MHV loop amplitudes in N=4 SYM are known to satisfy an exponentiation relation which allows for any loop amplitude to be determined using the knowledge of the one-loop case. Starting at six external particles this relation remains valid for the infrared-divergent terms, but a finite correction appears, called the remainder function. In this talk I will discuss how a similar notion can be applied to form factors, which are more generic, partially off-shell objects. In the first part I will illustrate the methods by focusing on protected operators. In the second part I will discuss non-protected operators belonging to the SU(2|3) sector, where the issues of renormalisation and mixing become relevant.