Absolute cross sections for the K-shell photoionization of C-like nitrogen ions were measured by employing the ion–photon merged-beam technique at the SOLEIL synchrotron radiation facility in Saint–Aubin, France. High-resolution spectroscopy with E/ΔE ≈ 7000 was achieved with the photon energy from 388 to 430 eV scanned with a band pass of 300 meV, and the 399.4–402 eV range with 60 meV. Experimental results are compared with theoretical predictions made from the multi-configuration Dirac–Fock and R-matrix methods. The interplay between experiment and theory enabled the identification and characterization of the strong 1s → 2p resonances observed in the spectra.