Extensive experiments in the Pb–Cu–Se–O–Br system at 400°C yielded single crystals of nine new compounds (Cu²⁺Pb₆(SeO₃)₄Br₆, Cu²⁺Pb₂(SeO₃)₂Br₂, Cu²⁺ ₃Pb_2.4(SeO₃)₅Br_0.8, Cu²⁺ ₂Pb(SeO₃)₂Br₂, Cu²⁺ ₄Pb(SeO₃)₄Br₂, [Cu²⁺ ₉Pb₂O₄](Cu⁺Br₂)(SeO₃)₄Br₅, [Cu²⁺ ₇PbO₃](Cu⁺Br)_0.35(SeO₃)₃Br₄, [Cu²⁺ ₈Pb₂O₄](Cu⁺Br)_1.5(SeO₃)₄Br₄, [Cu²⁺ ₆Pb₃O₄](Cu⁺Pb_1.27Br_3.54)(SeO₃)₄Br₂), all but one exhibiting new complex layered or open-framework architectures, organized via the host–guest principle. Five of these structures contain only bivalent copper: three with well ordered 2D structures and completely filled atomic positions, two structures have 3D frameworks. The four remaining compounds contain both, Cu²⁺ and Cu⁺, and comprise layers formed by edge- and vertex-sharing of oxocentered OCu²⁺ _4–nPb_n tetrahedra decorated with SeO₃ ²⁻ and Br⁻ anions. The interlayer spaces are filled by partially disordered Cu⁺–Br and Pb–Br associations. One remarkable feature of the latter group of compounds is the presence of tetrahedral (Cu²⁺)₄ complexes with arrangements derivable from a kagome network.