The e-Mobility Account Identifier (EMAID) is the corresponding data field to Contract ID, which is defined within ISO 15118-1.
EMAIDs in the definition of ISO-15118 have some representational flexibility due to optional elements.
The Hubject Plug and Charge ecosystem will therefore normalize all incoming IDs to match the following expression: /[A-Z]{2}[\dA-Z]{3}[\dA-Z]{9}/i
However the version with optional seperators (“-”) and check digit is allowed : /[a-z]{2}(-?)[\da-z]{3}\1[\da-z]{9}(\1[\da-z])?/i.
Nevertheless the Hubject ecosystem will always remove Hyphens from the EMAID due to the ISO15118-2 Protocol, where just max. 15 characters can be transfered between EV and EVSE.
ABNF from the ISO 15118-2:2014(E):
<EMAID> = <Country Code> <S> <Provider ID> <S> <eMA Instance> <S> <Check Digit>
Clients can still use it but the system will normalize to the form above (no seperators and captial letters).