In recent years the clinical success of T cell-based immunotherapy approaches has revolutionized treatment of solid tumors and hematological malignancies. However, still some patients do not respond to available therapies at all, others for limited time only. A promising low side-effect approach is peptide-based immunotherapy, which relies on specific immune recognition of tumor-associated human leucocyte antigen (HLA)-presented peptides. In this study, we developed a workflow for the immunopeptidome-guided design of off-the shelf warehouses for personalized peptide vaccines using the example of chronic lymphocyte leukemia (CLL). The so defined warehouses could provide the basis for different T cell-based immunotherapy approaches such as TCR-engineered T cell transfer or multi-peptide vaccinations. The warehouse approach enables a fast and cost-effective way to provide a personalized T cell-based immunotherapeutic approach. The here defined peptide warehouse is already utilized for a personalized multi-peptide vaccine trial (iVAC-XS15-CLL01, NCT04688385).