PAYE51015 | Employer returns: employer EOY penalties: ECS penalty reference numbers
From HM Revenue & Customs · PAYE Manual
ECS penalty reference numbers are automatically generated. Each reference number is made up as follows
The office number
PEN (for penalty)
The letter ‘P’ to indicate this is a S98A (2) TMA70 End of Year penalty. P will be shown regardless of whether the penalty relates to a ‘PAYE' employer or ‘SC / CIS' contractor
E (for ECS)
The consecutive number. The maximum number of ECS penalty charges for any one office number in any one year of Account is 99,999
The year of Account. This is the accounting year for the annual balance which ends on the last friday in October each year. For example the year of Account ending October 1999 will be shown as ‘99’
Employer reference. This excludes the office numeral
PEN denotes that it's an end of year penalty
EFI denotes that it's an E-File penalty
EYI denotes that it's an In Year penalty
NCA denotes that it's a P11D(b) penalty
N denotes that the penalty is for failing to file online
Example
123 PEN P E 456 99 A321 denotes
In Account 99
The 456th penalty for office number 123
For the employer record with the employer reference A321