[en] The Neutral Beam Test Facility (NBTF) will be the first ITER-like injector to be built with the objective of testing all the full scale components under operating conditions equivalent to ITER. During the EDA phase of ITER beam transmission calculations were performed to study the effects of the residual magnetic field of ITER on the beam transmission . As a result of these studies, a set of limits was found for the acceptable magnetic field at different stages of the beam transport. In recent years, further developments in the field of the beam source and acceleration system have been carried out. Studies of negative ion and extracted electron transport in the new systems (SINGAP accelerator) have lead to even more stringent conditions for the magnetic field in the grid area: a magnetic field of 0.1 mT could give rise to unacceptable power loads at the neutralizer leading edges due to interception of the stripped electrons trajectories. The Magnetic Field Reduction system of the ITER NBH(and)CD injectors was designed such as to reduce the stray magnetic field of ITER down to the required values, and finite element magnetic analyses were performed at that time which acknowledged an associated error greater than the acceptable magnetic field values at some critical areas. In view of the critical effect of even a small magnetic field, and the uncertainty of the predicted values, it seems necessary to install at the NBTF a set of coils able to reproduce the residual magnetic field inside the ITER injectors at different plasma and heating scenarios. This paper presents the design of the Residual Magnetic Field Coils (RMFC) to be installed at NBTF. It consists of 12 rectangular coils electrically grouped into 6 pairs, located above and below the beam line vessels and covering all the areas relevant for beam transport. At NBTF, the RMFC will be operated in a variety of electric current configurations in order to study the effect of the magnetic field on the beam transmission and the power deposition at various simulated ITER scenarios. The paper presents a discussion of the criteria entering the choice of coil design, of which the most relevant is the flexibility of achievable magnetic field scenarios. With the proposed set of coils the magnetic field can be varied independently at the Beam Source, Gap, Neutralizer and Residual Ion Dump areas. The final coil arrangement is presented and the detailed coil and support structures design are described. (author)