The changes below apply from 1 January 2008.

From now on the opening of the slot will be slightly larger and can be lower or higher from the ground.

The new minimum opening will be 23 cm x 3xm but existing letterboxes with an opening of 22 x 3 cm will remain in force, provided that the letterbox was installed before 1 January 2008.
The lower edge of the opening must be at least 70 cm high and the upper edge of the opening must not be higher than 170 cm.
In specific cases, the position of the slot can be extended between a minimum of 40 cm and a maximum of 180 cm. Examples are letterbox openings in the façade of an existing building that was put into use before 1 January 2008 or groups of letterboxes belonging together (at least 4).
A minimum standard has been set for the dimensions of the letterboxes:

The letterbox must be large enough to receive an unfolded C4 format item (229 mm by 324 mm) with a thickness of 24 mm without being damaged. Letterboxes which are not large enough to receive an unfolded C4 format item with a thickness of 24 mm without being damaged remain regulated, however, on condition that the letterbox was installed before 1 January 2008.
There is also a new provision for the placement of the house number:

In the event that the house number is not legible from the place where the letterbox is located, the house number must be clearly and legibly displayed on or near the letterbox.

The provisions for good accessibility of the letterbox remain unchanged