T, R. v [2021] EWCA Crim 1474, October 14, 2021, at paragraph 8:

In our view, the judge needs to look at all the factors in the round when considering the extent, if at all, of any reduction in sentence for information provided to the authorities. Whilst it is legitimate, therefore, to consider the extent of any financial reward already received by the accused in this context, it must be remembered that these two incentives – a financial reward and a reduction in sentence – are complementary means of demonstrating to offenders “that it is worth their while to disclose the criminal activities of others for the benefit of the law-abiding public in general” (Simon (1988) 87 Cr App R 407 at 411). It would undermine the proper functioning of this tried and tested means of gaining valuable intelligence if an accused was to conclude that having been rewarded financially any reduction in sentence would be slight, non-existent or significantly reduced. It follows, that unless the financial reward has been exceptionally generous, this factor will play only a small, if any, part in the judge’s calculation.