17 Trade and other payables
| | 2016 | 2015 |
Trade payables | 2,980 | 2,814 |
Group companies Bouwinvest | - | 1 |
Rent invoiced in advance | 4,393 | 4,566 |
Tenant deposits | 479 | 363 |
Service charge payments | 595 | 1,141 |
Promotion costs | 101 | 34 |
Tax | - | 43 |
Other payables | 171 | 218 |
Balance as at 31 December | 8,719 | 9,180 |
The other payables relate to invoices yet to be received for maintenance of and investments in the portfolio.