In the Twelve Galaxies, a krin was a unit of currency, one of which was equal to 200 kavlons, 90 forvalars, or 4,000 trynties. The Thirteenth Doctor was unfamiliar with this currency.
The grand prize of the final Rally of the Twelve Galaxies was 3.2 trillion krin. In an unprecedented act, Ilin was coerced into splitting the prize to be claimed by joint winners Angstrom and Epzo. (TV: The Ghost Monument)