The 15th workshop of the Pathfinder HI Survey Coordination Committee (PHISCC) was held last week in Cagliari, Sardinia, with good representation from members of the ASKAP spectral-line survey teams and talks on new results from DINGO, FLASH, GASKAP and WALLABY. PHISCC brings together the community working on HI research with SKA pathfinder and precursor telescopes and covers both scientific and technical topics. With most major new and upgraded facilities for 21 cm research operational, the PHISCC 2025 workshop focussed on the latest HI results in the broader multi-wavelength context and in connection with theory and simulations. The first three days were comprised of workshop sessions, with the final two days devoted to breakout sessions.