| As at December 31, 2021 | As at December 31, 2021 | |
| OTHER CURRENT LIABILITIES | ||
| VAT liabilities | 564 | 540 |
| Excise tax liabilities | 27 | 33 |
| Environmental fees | 240 | 202 |
| Payroll liabilities | 257 | 284 |
| Bonuses for employees | 277 | 272 |
| Unused annual holiday leave | 96 | 113 |
| Liabilities due to Voluntary Leave Programs | 1 | 1 |
| Bonuses for the Management Board | 17 | 20 |
| Estimated liabilities concerning other employee benefits | 5 | 5 |
| Personal income tax | 99 | 95 |
| Liabilities from social insurances | 255 | 269 |
| Liabilities related to a contract | 344 | 296 |
| Liabilities related to dividends | 4 | 7 |
| Other | 72 | 66 |
| TOTAL OTHER CURRENT LIABILITIES | 2,258 | 2,203 |
Environmental fees relate mainly to charges for the use of water and gas emission in conventional power plants as well as exploitation charges paid by coal mines. The “Other” position comprises mainly payments to the Employment Pension Program, the Social Fund and the State Fund for Rehabilitation of Persons with Disabilities.
Liabilities related to a contract
Contract liabilities mainly include advances for deliveries and prepayments by customers for connections to the distribution grid and electricity consumption forecasts for future periods. In 2021, the Group recognised revenue of PLN 147 million (PLN 165 million in 2020), which was included in the balance of contract liabilities at the beginning of the period.