Employer Alignment Submission (EAS) is used to send in details of employee data held in the payroll software to HMRC so that HMRC and employer data for the active employment (along with details of starters and leavers in the current tax year) can be matched.
HMRC suggest that an EAS is required for employers with a large PAYE scheme (over 250 employees) or with a payroll administered by two or more payroll systems.
In most cases, for employers with less than 250 employees operated from within a single payroll dataset, the Employer Alignment will be performed by HMRC when a first Full Payment Submission (FPS) is submitted. If an employer still wishes to send an EAS for Payroll Alignment, they may do so.
We recommend that an EAS is submitted at the start of new tax year (6th April). This is especially important if you have employees with different 'Payment frequency' setup in the payroll. You cannot submit EAS again during the tax year.
Once the EAS has been successfully submitted, the employer is considered to have joined RTI and can start sending Full Payment Submission (FPS) immediately.