How social security contributions for self-insured persons are calculated: step by step

17 October 2026 · 7 min read · The Danak team

The social security contribution for a given month is the product of two factors: the chosen insurance income and the rate for the relevant fund. The calculation is the same for all months in which you carry on your activity and does not change with the actual income you receive during the month. Top-up contributions — when your annual income results in higher insurance income — come after you file your annual return.

What is the formula

For each of the social insurance funds, the contribution is calculated in the same way:

Contribution = chosen insurance income × fund rate

The chosen insurance income is the amount on which you decide to make advance payments during the year. For 2026, it must be between 550.66 € and 2,111.64 € per month for the period January to July and between 620.2 € and 2,300 € for the period August to December. The rate is the percentage laid down by law for each fund.

The sum of the contributions for all funds gives the total monthly amount you owe.

Rates by fund

Self-insured persons pay into three or four funds, depending on their date of birth and their choice on sickness and maternity insurance.

For those born after 31 December 1959

Mandatory funds:

• Pension (Pension Fund, фонд „Пенсии"): 14.8 %
• Universal Pension Fund (УПФ): 5 %
• Health insurance: 8 %

Optional:

• Sickness and maternity (ОЗМ, Общо заболяване и майчинство): 3.5 %

The total rate for mandatory funds is 27.8 %. With sickness and maternity insurance elected, it becomes 31.3 %.

For those born before 1 January 1960

Mandatory funds:

• Pension (Pension Fund, фонд „Пенсии"): 19.8 %
• Health insurance: 8 %

Persons born before 1960 do not participate in a universal pension fund but pay the entire pension contribution to the state social insurance.

Optional:

• Sickness and maternity (ОЗМ): 3.5 %

The total rate for mandatory funds is again 27.8 %, and with sickness and maternity elected it is 31.3 %. The difference is only in the distribution between the Pension Fund and the universal pension fund.

Step by step: example at minimum insurance income

Take a person born in 1985 who chooses to insure on the minimum insurance income and has not elected sickness and maternity insurance.

January to July 2026 (minimum income 550.66 €):

August to December 2026 (minimum income 620.2 €):

The change from August comes from the new minimum amount set by the State Social Insurance Budget Act for 2026.

Step by step: example at maximum insurance income

The same person chooses to insure on the maximum insurance income for August to December and again without sickness and maternity:

The calculation is the same all year because the chosen income does not change. The relationship is clear: higher insurance income gives higher monthly contributions but also higher pension entitlement and health insurance rights.

If you have elected sickness and maternity insurance

When a self-insured person elects to pay for sickness and maternity as well, another contribution is added to the calculation:

At minimum income 550.66 € (January to July):

At maximum income 2,300 € (August to December):

Sickness and maternity insurance gives the right to cash benefits in the event of temporary incapacity for work and maternity but is mandatory only for certain categories of persons (for example craftspeople). Others choose whether to include it.

Why contributions do not depend on monthly income

Self-insured persons pay in advance on insurance income they have chosen, not on the income actually received during the month. Actual income may vary considerably from month to month — but the monthly contribution remains the same because it is calculated on the chosen income you declared at the beginning of the year or on a change.

The chosen income may be lower or higher than your average actual income — but not lower than the minimum and not higher than the maximum amount for the year. This approach gives predictability: you know in advance how much you will owe each month.

Where annual equalization comes in

After the end of the year, your tax return under Art. 50 of the Personal Income Tax Act (ЗДДФЛ) shows the total taxable financial result, from which the final insurance income is also determined. If it turns out higher than the chosen income, you pay additional contributions on the difference together with the deadline for filing the return — usually by 30 April of the following year (Art. 6(9) of the Social Insurance Code, КСО). If it turns out lower but not below the minimum amount, you owe nothing additional.

The equalization is calculated in Declaration form 6 (Декларация образец 6), which you file at the same time as the annual tax return.

You will find details of the annual calculation in the guide to social security contributions for self-insured persons.

Where to check the calculation

The free calculator (app:calculator) on Danak calculates monthly contributions by fund on the basis of the chosen insurance income, shows the legal basis for each rate and gives the annual picture with top-up contributions if necessary. The calculations are made according to the parameters in force for the relevant year.

What comes next

You choose the insurance income and declare it with Declaration form 1 (Декларация образец 1) to the National Revenue Agency (НАП) — by the 25th of the month following the start of the activity or a change. Contributions are also paid by the 25th of the following month using the payment type codes:

• 551111 — pension
• 581111 — universal pension fund
• 561111 — health insurance
• Each fund is paid separately to the NRA accounts.

The declaration shows the chosen income and the insurance base. Payment follows the calculation described here.

Frequently asked questions

How is the contribution for each social insurance fund calculated?

The contribution is the product of the chosen insurance income and the fund rate. For example, with a chosen income of 620.2 € (minimum for August to December 2026) and a health insurance rate of 8 %, the contribution is 620.2 × 0.08 = 49.62 €.

Why does my monthly contribution not change when my income varies?

Social security contributions are paid in advance on insurance income you have chosen, not on income actually received during the month. Equalization comes annually when the final insurance income is determined on the basis of the tax return.

What is the difference in insurance for those born before and after 1960?

Those born after 31 December 1959 pay 14.8 % to the Pension Fund and 5 % to a universal pension fund. Those born before 1 January 1960 pay 19.8 % to the Pension Fund only and do not participate in a universal pension fund. The total rate in both cases is 27.8 % for mandatory funds.

How is the total monthly contribution calculated?

The sum of the contributions for all funds gives the total monthly amount. For example, with a chosen income of 550.66 € (minimum January to July 2026) and without sickness and maternity insurance: pension 81.50 € + UPF 27.53 € + health 44.05 € = 153.08 € total.

What is sickness and maternity insurance and how is the contribution calculated?

Sickness and maternity insurance is optional for most self-insured persons and gives the right to cash benefits in the event of temporary incapacity for work and maternity. The contribution is 3.5 % of the chosen insurance income. For example, at maximum income of 2,300 € (August to December 2026), the contribution is 2,300 × 0.035 = 80.50 €.

Sources

• НОИ — осигурителен доход и прагове (in Bulgarian)
• Кодекс за социално осигуряване (in Bulgarian)
• НАП — самоосигуряващи се лица (in Bulgarian)
• НАП — банкови сметки за плащане (in Bulgarian)