Reference

Figured Bass 7th-chord Symbols

As with triads, we can use the same symbols for any seventh chord (for more information, see Baroque Chord Symbols)

The complete chord symbol of the dominant 7th chord appears below the first example. The same symbols can be used on anyr 7th chord type. In the second example, the simplified symbol appears, being the one that is usually used:

Root position:

First inversion:

Second inversion:

Third inversion:

Some schools use a different symbol for dominant 7th and diminished and half-diminished 7th chords:

Dominant 7th:

Diminished 7th:

Half-diminished 7th:

See: Baroque Chord Symbols, Triad Symbols, Alterations in Figured Bass