Hand-scoring errors are known to occur on a range of psychological tests. The present study conducts an investigation into the existence of scoring errors by 27 professional occupational psychologists using the Rothwell - Miller Interest Blank (RMIB). Building on investigations into the impact of work allocation practices on work quality in other professions, the present study explored whether psychologist scoring error rates differed between three work allocation systems. Data from 1175 completed RMIB survey forms indicated that error rates for the three systems ranged from 5 to 16.3 per cent, with the self-managed work allocation system resulting in the lowest error rate. The discussion focuses on possible ways for psychologists to overcome scoring error rates with the RMIB and the potential implications these results have for allocating case work to psychologists. Suggestions for test developers and organisations designing work allocation systems are proffered.