<p>Venus and Earth are alike in size and composition and share similarly productive histories of volatile degassing. Yet while chlorine is concentrated in Earth’s surface reservoirs, it is nearly absent from the atmosphere of Venus. The fate of Venusian chlorine offers insights into the evolution of magmatism and history of volcanic degassing on Venus and similar telluric planets. Here we explore the potential for sodalite (Na₈Al₆Si₆O₂₄Cl₂), crystallised from erupted volcanics, to act as a long-term chlorine-sink in planetary crust. By estimating alkaline melt production on Venus, we constrain chlorine sequestration into sodalite-stable alkaline volcanics. We find that phonolites containing up to 7 mol% sodalite can be produced through 91–98% fractionation of low-degree partial melts originating from the Venusian upper mantle. Overall, just ~750 m of alkaline volcanic resurfacing has the capacity to sequester an Earth-like chlorine budget within sodalite-bearing lithologies.</p>