Several investigations have shown that ReBCO coils wound without turn-to-turn insulation are self-quench protecting due to the current bypass through layers. However, some of the obstacles that this type of magnets face are charging and discharging delays, directly related to the generation of eddy currents increased by the low contact resistance between turns. The inter-tape contact resistance plays a key role to address the disadvantages that no insulation brings to magnet performance and benefit from the current sharing feature. In this work we propose an electric-circuit model to describe the inter-tape contact resistance and its impact on the current sharing between tapes for REBCO cables and magnets. With the developed model, we present the ideal contact resistance that can suppress the inter-tape eddy currents and enhance the current sharing between tapes. We also report quench experiments on short REBCO tapes to validate the model. Our model is expected to provide insight into the current sharing and target values for inter-tape contact resistance in REBCO cables and magnets for various applications.