  Searches for anomalous neutral triple gauge boson couplings (NTGCs) provide
important tests for the gauge structure of the standard model. In SMEFT
("standard model effective field theory") NTGCs appear only at the level of
dimension-8 operators. While the phenomenology of these operators has been
discussed extensively in the literature, renormalizable UV models that can
generate these operators are scarce. In this work, we study a variety of
extensions of the SM with heavy fermions and calculate their matching to d = 8
NTGC operators. We point out that the complete matching of UV models requires
four different CP-conserving d = 8 operators and that the single CPC d = 8
operator, most commonly used by the experimental collaborations, does not
describe all possible NTGC form factors. Despite stringent experimental
constraints on NTGCs, limits on the scale of UV models are relatively weak,
because their contributions are doubly suppressed (being d = 8 and 1-loop). We
suggest a series of benchmark UV scenarios suitable for interpreting searches
for NTGCs in the upcoming LHC runs, obtain their current limits and provide
estimates for the expected sensitivity of the high-luminosity LHC.
