A series of new dinuclear copper complexes with a tetraphosphane bridging ligand, [{(pz4B)Cu}2(µ‐tpbz)] (1), [{(pz2BH2)Cu}2(µ‐tpbz)] (2), and [{(tz2BH2)Cu}2(µ‐tpbz)] (3) [tpbz = 1,2,4,5‐tetrakis(diphenylphosphanyl)benzene, pz4B = tetrakis(pyrazol‐1‐yl)borate, pz2BH2 = bis(pyrazol‐1‐yl)borohydrate, and tz2BH2 = bis(1,2,4‐triazol‐1‐yl)borohydrate], have been synthesized and structurally characterized. The CuI atoms in these complexes are four‐coordinate and adopt a tetrahedral coordination geometry. In each complex, the copper centers are bridged by a tpbz ligand and each CuI is further terminally chelated by a borate diimine anion. The central phenylene ring and the phosphine atoms of the tpbz ligand are essentially planar. The two CuI atoms in each molecule are located above and below the (P2C6H2P2) mean plane, respectively, leading to a chair‐like conformation for the [Cu](P2C6H2P2)[Cu] fragment. The distances between the CuI atoms in each complex are about 8.7 Å. In the solid state, these complexes are emissive and exhibit yellow–orange photoluminescence [emission peaks, λmax = 580 nm (1), 569 nm (2), 540 nm (3)] with lifetimes of 7.4–20.5 µs and quantum yields Φ = 0.07–0.45 at room temperature. Theoretical and experimental results indicate that these complexes have the lowest singlet (S1) state and the lowest triplet (T1) state with very close energy levels, and display thermally activated delayed fluorescence (TADF) at ambient temperature.