Application of De Minimis
The de minimis rule specifies that all energy related charges at a premise be subject to reduced rate VAT if the total usage at a premise does not exceed a certain threshold. To determine if de minimis applies, the total billed consumption for a premise must therefore be known. However, energy usage at a premise may be measured with several meters and billed by multiple service agreements. To ensure that the final billed consumption for the premise is used to determine if de minimis applies, all service agreements for an account of a given service type at a given premise should be billed together and de minimis should be checked after the bill segments have been generated. In addition, all bill segments on one bill for consumption at a given premise must be for the same bill period.
Note: 
Bill segments from different periods may not appear on the same bill. If a bill segment is canceled, all bill segments associated with consumption at a given premise for the same service type must be canceled and re-billed together. You cannot re-bill the bill segment on a bill for a different period.
An Apply De Minimis Rule Customer Class – Pre Bill Completion algorithm type CPBC-DMCH is supplied with the base package that checks for de minimis at bill completion time. The base bill completion algorithm type checks that for any service agreement that was billed, bill segments for all the account's service agreements with the same service type and characteristic premise exist on the bill. It then calculates the total consumption for the premise and determines if de minimis applies. If de minimis applies, it sets a bill characteristic whose value is the premise ID to indicate that de minimis applies and regenerates the bill segment. Refer to the Apply De Minimis Rule algorithm type CPBC-DMCH for more information on how this type of algorithm operates.
For calculation rule-based rates, the Apply VAT to Cross-Referenced Charges calculation rule business object (C1–ApplyVatToCrossRefCharge) calculates standard and reduced rate VAT and applies the de minimis rule if the bill characteristic for de minimis is found. Refer to Calculation of VAT for more information. Note that during the initial generation of each bill segment, the characteristic will not exist and standard rate VAT will be applied. This means that if you look at a bill before it is complete, VAT may not be accurately reflected.
For component-based rates, the Apply VAT to Cross-Referenced RCs Rate Component – Calculation Algorithm algorithm type that calculates standard and reduced rate VAT (RCAM-VAT) applies the de minimis rule if the bill characteristic for de minimis is found. Refer to Calculation of VAT for more information. Note that during the initial generation of each bill segment, the characteristic will not exist and standard rate VAT will be applied. This means that if you look at a bill before it is complete, VAT may not be accurately reflected.
Note: 
Batch billing cannot regenerate re-billed bill segments. If you cancel and rebill a bill segment, you should complete the bill on-line so that the re-billed bill segments can be regenerated if de minimis applies.