Total Weighing Solutions can provide an in-house ISO calibration certificate which is traceable to National Standards. Please see the Accessories tab. Only one certificate is needed per batch of weights and must be added at time of ordering.
Alternatively, you can have the weight verified by UKAS. Please choose the UKAS verified option on the weight. Then please remember to add the UKAS certificate option from the Accessories tab. Again, only one certificate is required per batch of weights.