<p>Neutron Resonance Transmission Analysis (NRTA) is a highly sensitive, non-destructive technique for nuclear material characterisation, but its application has been limited by its reliance on large, fixed, and costly installations. Here, we present a compact mobile NRTA system utilising a small ²⁵²Cf spontaneous neutron source, designated as a prototype “table-top NRTA system”, to analyse nuclear materials, offering a mobile and cost-effective alternative to accelerators or deuterium-tritium generators. The pilot system, measuring 130 cm × 50 cm × 50 cm with a 42 cm flight path, enables time-of-flight measurements on nuclear material samples. The system’s performance was demonstrated through NRTA measurements of simulated samples, including indium, hafnium, and cadmium metal plates. The experimental transmission spectra were compared with theoretical predictions using the PHITS Monte Carlo simulation and the JENDL-5 nuclear data library, enabling isotope identification below 5 eV. The obtained results underscore the system’s potential as a complementary tool for nuclear security and safeguards verification, particularly in scenarios where access to large accelerator or reactor facilities is impractical, and where mobility, compactness, and cost-effectiveness are prioritised over throughput.</p>