The States police say that one set of three notes was tendered in a St Helier licensed premises on Wednesday evening.
Another note was given to a takeaway delivery driver at Les Quennevais late on the same night.
The force is investigating the use of forged notes at two other businesses in St Helier.
One batch bears the serial number: CD076622. The second batch bears serial number QC416700.
Anyone with information is being asked to phone the States police on 612612.