Try this..

FOR sp_null_rec IN sp_null_cur
LOOP
BEGIN

SELECT premise_id
INTO v_premise_id
FROM cisif_service_point
WHERE sp_id = sp_null_rec.sp_id;
EXCEPTION
WHEN NO_DATA_FOUND THEN
variablenotfound := variablenotfound + 1;
NULL;
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Error: ' || SQLERRM || ' FOR ' || sp_null_rec.sp_id);
END;

EXIT WHEN sp_null_cur%NOTFOUND;
END LOOP;