In EU24 filing process, a so call “Entry Key” is required for the following purpose:​

• For Vessel Operators to file Arrival Notification and diversion request
• For Filers (carrier or third party filers) to file the initial ENS and amendments

The "Entry Key" comprises of the following data elements:

• the mode of transport at the Border
• the identification of the means of transport crossing the border (IMO vessel number)
• the date of expected arrival at the declared customs office of first entry
• the country code of the declared customs office of first entry
• the declared first place of arrival code