Why aren’t the employer’s/employee’s NIS contributions accurate on the NI184?

Revised on September 17, 2026

This is a common issue that users experience. These are the three common mistakes users make when experiencing inaccurate contributions on the NI184:

1

An employee was set to a statutory override, but the contributions have not been adjusted

A statutory override is a worksheet setting that lets the user bypass the system’s automatic calculations and manually enter statutory adjustments. A common mistake users make is by adjusting the employee’s contribution, but not the employer’s. This results in an inaccurate representation of the true NIS contributions on the NI184.

Solution

Ensure that both the employer’s/employee’s contributions (highlighted in black on the worksheet) is accurate. Also, always generate a NIS Deductions Report before creating a NI184. This highlights any abnormalities in the employer’s and employee’s contribution.

2

Employee's working period doesn't include a Monday

If an employee has left or entered the pay cycle early, the user must ensure that a Monday falls within their date range. Without this, the NI184 cannot correctly categorize the contributions to the appropriate week.

Solution

Edit the employee’s work period on the worksheet to ensure that a Monday is included in their start or end date.

3

'Exclude NIS' or 'Class Z' settings were enabled accidentally

TTPay automatically sets an employee to Class Z if they are aged over 65 or under 16. However, apart from the Statutory Override, there are still ways NIS can be excluded manually:

  • By enabling the Exclude NIS box under Statutory Options in the employee’s window
  • Manually setting the employee to Class Z in the employee’s window or the worksheet.

Solution

Print the NIS Deductions Report. This will highlight which employees are marked as Class Z, allowing the user to confirm whether each one should actually be Class Z or not.

We always recommend that you print a NIS Deductions Report before generating the NI184. This highlights any abnormalities in the employer’s and employee’s contribution. If you are unsure on the rate of contributions, check the National Insurance Board’s page to view the current statutory rates.