Magnetic field estimates for accreting neutron stars in massive binary systems and models of magnetic field decay

► The magnetic fields of NSs in 40 Be/X-ray binary systems are estimated using different methods. ► Magnetic field distributions are constructed for each method and compared to theoretical predictions. ► Most of the methods are shown to over-produce NSs with high magnetic fields larger than few x1013∼G. ► Best agreement was achieved for the estimates based on the recent quasi-spherical accretion model by Shakura et al. (2012).