It is the difference between the proportional annual income threshold and the gross assessment amount for regular pay. It is created each month for each social insurance category (health insurance, unemployment insurance, pension insurance and nursing insurance).

It consists of:

• the difference between the income threshold and gross assessment amount for regular pay and
• the SI income threshold deficit from the previous month (as it relates to the last payroll result of the current year for the same employer).

At the start of the first payroll run of the year, the SI income threshold deficit from the previous year is stored, and the SI income threshold deficit for the current year is set to zero.

The SI income threshold deficit is used as the income threshold for one-time payments, for which you would otherwise not calculate contributions.

If you do not take the HI income threshold deficit into account, only the amount up to the income threshold is used to calculate contributions. That is, 6,000 DM regular pay and 150 DM one-time payments. The remaining 1,350 DM is not taken into account for contributions.

The SI income deficit threshold is used in this case. To calculate contributions on one-time payments, the SI income threshold deficit for the relevant SI category (the HI income threshold deficit for the above example) is used as the assessment threshold. In this example, the HI income threshold deficit is the 150 DM difference between the regular pay and the income threshold, and the 1,000 DM HI income threshold deficit from the previous month. This is, consequently, 1,150 DM. Using this income threshold, contributions are calculated on the 1,500 DM one-time payment. 350 DM is not taken into account.

In the standard system, the SI income threshold deficit is stored in its own secondary wage type for each social insurance category.