When is the carbaldehyde suffix correct?
Both names, ‘benzenecarbaldehyde’ and ‘benzaldehyde’, are unambiguous and describe the same compound. However, the preferred IUPAC name (PIN) is ‘benzaldehyde’.
Concerning aldehydes, the current version of Nomenclature of Organic Chemistry – IUPAC Recommendations and Preferred Names 2013 (Blue Book) reads as follows:

P-66.6.1 Systematic names of aldehydes
Aldehydes are systematically named in three ways:
(1) substitutively, using the suffixes ‘al’ for $\ce{-(C)HO}$ and ‘carbaldehyde’ for $\ce{-CHO}$;
(2) by changing the ‘ic acid’ or ‘oic acid’ endings of retained names of carboxylic acids into ‘aldehyde’; the nomenclatural properties of acids are transferred to aldehydes; thus, preferred names of aldehydes correspond to preferred names of acids, and carboxylic acids that are not substitutable generate nonsubstitutable aldehydes;
(3) by using the prefixes ‘oxo’, denoting $\ce{=O}$, or ‘formyl-’, denoting the substituent group $\ce{-CHO}$.

In particular,

P-66.6.1.1.3 The suffix ‘carbaldehyde’ is used when the $\ce{-CHO}$ group is attached to a carbon atom of a ring or ring system, or to a heteroatom.

For example, ‘cyclohexanecarbaldehyde’ is a PIN.

However, according to P-66.6.1.2.1, the PIN for the compound given in the question is ‘benzaldehyde’. (This name is analogous to the preferred name of the corresponding acid ‘benzoic acid’, see P-66.6.1 (2) above.)

Nevertheless, according to P-66.6.1.2.2, the PINs for phthalaldehyde and terephthalaldehyde are the systematic names ‘benzene-1,2-dicarbaldehyde’ and ‘benzene-1,4-dicarbaldehyde’, respectively. (These names are analogous to the preferred names of the corresponding acids ‘benzene-1,2-dicarboxylic acid’ [not ‘phthalic acid’] and ‘benzene-1,4-dicarboxylic acid’ [not ‘terephthalic acid’], respectively.)