An onboard unit for levying toll for a vehicle, comprising: a satellite navigation receiver for generating position fixes (p i); a memory for recording geoobjects (ob j); a radio interface; and a processor connected to these components (5, 9, 11), which is configured to generate toll data (tr) from a geographical comparison of position fixes (p i) with geoobjects (ob j) in a digital map and to transmit this data via the radio interface; characterised in that the memory has: an index memory region (M 3), in which an index tree for geoobjects (ob j) is stored, of which the outermost branches (b 1) are each assigned to a cell (c m) of the digital map and carry a leaf (lv m) with identifiers (id j) of geoobjects (ob j) of this cell (c m), a first static object memory region (M 1), in which a primary list with geoobjects (ob j) and identifiers (id j) thereof is stored, and a second object memory region (M 2), which can be written dynamically via the radio interface and in which at least one secondary list with geoobjects (ob j) and identifiers (id j) thereof is stored; wherein at least one leaf (lv m) of the index tree contains a reference to a secondary list; and wherein the processor is configured, upon accessing a geoobject (ob j) via a leaf (lv m), when this leaf contains a reference to a secondary list, to use the secondary list as a matter of priority before the primary list. a satellite navigation receiver for generating position fixes (p i); a memory for recording geoobjects (ob j); a radio interface; and a processor connected to these components (5, 9, 11), which is configured to generate toll data (tr) from a geographical comparison of position fixes (p i) with geoobjects (ob j) in a digital map and to transmit this data via the radio interface; characterised in that the memory has: an index memory region (M 3), in which an index tree for geoobjects (ob j) is stored, of which the outermost branches (b 1) are each assigned to a cell (c m) of the digital map and carry a leaf (lv m) with identifiers (id j) of geoobjects (ob j) of this cell (c m), a first static object memory region (M 1), in which a primary list with geoobjects (ob j) and identifiers (id j) thereof is stored, and a second object memory region (M 2), which can be written dynamically via the radio interface and in which at least one secondary list with geoobjects (ob j) and identifiers (id j) thereof is stored; wherein at least one leaf (lv m) of the index tree contains a reference to a secondary list; and wherein the processor is configured, upon accessing a geoobject (ob j) via a leaf (lv m), when this leaf contains a reference to a secondary list, to use the secondary list as a matter of priority before the primary list. an index memory region (M 3), in which an index tree for geoobjects (ob j) is stored, of which the outermost branches (b 1) are each assigned to a cell (c m) of the digital map and carry a leaf (lv m) with identifiers (id j) of geoobjects (ob j) of this cell (c m), a first static object memory region (M 1), in which a primary list with geoobjects (ob j) and identifiers (id j) thereof is stored, and a second object memory region (M 2), which can be written dynamically via the radio interface and in which at least one secondary list with geoobjects (ob j) and identifiers (id j) thereof is stored; wherein at least one leaf (lv m) of the index tree contains a reference to a secondary list; and wherein the processor is configured, upon accessing a geoobject (ob j) via a leaf (lv m), when this leaf contains a reference to a secondary list, to use the secondary list as a matter of priority before the primary list.