A belt retractor for a vehicle seat belt includes a rotatably supported belt reel (12) from which webbing can be unwound, a force limiting means which in a force limiting phase permits controlled webbing extension in the webbing extension direction when the belt reel (12) is blocked and a particular force threshold is exceeded, and a change-over device for carrying out a change-over operation before and/or during the force limiting phase in which it is changed from a first force level to a second force level. The change-over device includes a control means adapted to trigger or inhibit the change-over operation at least in response to the recognition of an installed child safety seat (34).