This paper examines the stability of the benefit transfer function across 42 recreational forests in the British Isles. A working definition of reliable function transfer is put forward, and a suitable statistical test is provided. A novel split sample method is used to test the sensitivity of the models’ log-likelihood values to the removal of contingent valuation (CV) responses collected at individual forest sites. We find that a stable function improves our measure of transfer reliability, but not by much. We conclude that, in empirical studies on transferability, considerations of function stability are secondary to the availability and quality of site attribute data. Modellers’ can study the advantages of transfer function stability vis-à-vis the value of additional information on recreation site attributes.