In the Netherlands, to provide antigen‐negative red cells for certain groups of patients, the majority of donors is serologically typed for ABO, RhCcDEe and K and a subset of donors for clinically relevant systems (e.g. Fy, Jk, MNSs). Complete phenotyping of all blood donors, for all blood group antigens including high frequency antigens, is too laborious and simply not feasible, because of the lack of sufficient and high‐quality typing reagents. For most blood group systems the molecular basis is known and found to be a single nucleotide polymorphism (SNP). In the last years, methods were developed facilitating high‐throughput blood group genotyping by glass‐based DNA microarrays. By this so‐called chiptechnology the phenotype of a donor for all clinically relevant (including HFA) red cell antigens can be simply predicted by running a single assay. Typing of platelet antigens and perhaps also HLA can be included as well. Therefore, high‐throughput genotyping or chiptechnology promises the future availability of a completely typed red cell and platelet inventory. A disadvantage of genotyping is false positive or negative results, due to currently unidentified or newly occurring mutations leading to null alleles or mispriming. Large‐scale studies of blood group antigen typing including different ethnic groups are required to determine the error rate. An advantage of the use of blood group genotyping assays is improved detection of ‘weak phenotypic signals’, for example weak‐D or Fyx antigens will be correctly identified by genotyping. If all red cells units are routinely completely typed a less restricted policy on preventive matching for clinically relevant blood group systems can be implement. Thus, in more patients or even in all blood recipients it may become possible to avoid alloimmunization with the benefit of a reduction in the occurrence of severe transfusion reactions (for example delayed haemolytic transfusion reactions by Jka alloantibodies) or a decreased survival time of transfused cells. Furthermore it will reduce costs and delays in provision of antigen‐negative red cells. Thus, if the challenge can be met to develop the current microarrays or chiptechnology into systems that meet the throughput and quality demands of the blood bank, this can lead to an important change in transfusion policy.