17 Trade and other payables
| | 2017 | 2016 |
Trade payables | 826 | 2,980 |
Rent invoiced in advance | 5,074 | 4,393 |
Group companies Bouwinvest | 1,627 | - |
Tenant deposits | 884 | 479 |
Service charge payments | 566 | 595 |
Promotion costs | 167 | 101 |
Tax | 67 | - |
Other payables | 708 | 171 |
Balance as at 31 December | 9,919 | 8,719 |
The other payables relate to invoices yet to be received for maintenance of and investments in the portfolio.