diff --git a/services/integration/doorLockCharges.js b/services/integration/doorLockCharges.js
index 4682d4e..cdefd66 100644
--- a/services/integration/doorLockCharges.js
+++ b/services/integration/doorLockCharges.js
@@ -255,9 +255,8 @@ const analyseReservation = (reservation) => {
                         }
 
                         let timeIntervalsToChargeBefore = Math.floor(timeDifferenceFromUnlockEntry / UNSCHEDULED_TIME_RESOLUTION);
-                        if (timeDifferenceFromUnlockEntry < UNSCHEDULED_USE_INITIAL_TIME_SEGMENT_LENGTH){
-                            timeIntervalsToChargeBefore = 0;
-                        }
+                        timeIntervalsToChargeBefore -= 1; // Remove first N minutes, N = UNSCHEDULED_TIME_RESOLUTION
+
                         const totalChargeFeeBefore = timeIntervalsToChargeBefore * UNSCHEDULED_CHARGE_PRICE;
                         const chargeBefore = totalChargeFeeBefore > 0;
 
@@ -267,9 +266,8 @@ const analyseReservation = (reservation) => {
                             timeDifferenceFromLockEntry = lockTime.diff(currentReservationEnd, 'minutes');
                         }
                         let timeIntervalsToChargeAfter = Math.floor(timeDifferenceFromLockEntry / UNSCHEDULED_TIME_RESOLUTION);
-                        if (timeDifferenceFromLockEntry < UNSCHEDULED_USE_INITIAL_TIME_SEGMENT_LENGTH){
-                            timeIntervalsToChargeAfter = 0;
-                        }
+                        timeIntervalsToChargeAfter -= 1; // Remove first N minutes, N = UNSCHEDULED_TIME_RESOLUTION
+
                         const totalChargeFeeAfter = timeIntervalsToChargeAfter * UNSCHEDULED_CHARGE_PRICE;
                         const chargeAfter = totalChargeFeeAfter > 0;