The current configuration of JET with ITER-like Wall (ILW) is the best available proxy for the ITER first wall. Beryllium redistribution in JET-ILW can be used for estimates of its migration in ITER. To trace it, a localized isotopic Be marker has been implemented. A bulk 9Be tile has been enriched with 10Be up to atomic concentrations of 1.7x 10^9 and installed at the inner midplane of JET before the campaign. During the 2012 shutdown over 100 surface samples were taken non destructively from surfaces of two toroidally opposite limiter beams. The absolute areal densities of the marker were inferred from 10Be atomic concentration in each sample, measured with Accelerator Mass Spectrometry with sensitivity <1014. The results of marker mapping are compared with predictions made with the ASCOT orbit following code.