diff --git a/core/planner/planner.go b/core/planner/planner.go
index c0bbe7ecb9c..fe34af7f71e 100644
--- a/core/planner/planner.go
+++ b/core/planner/planner.go
@@ -154,6 +154,11 @@ func (t *Planner) Plan(requiredDuration, precondition time.Duration, targetTime
 
 	rates = clampRates(rates, now, targetTime)
 
+	// check if rate coverage is sufficient for planning
+	if len(rates) == 0 || rates[len(rates)-1].End.Sub(rates[0].Start) < requiredDuration {
+		return simplePlan
+	}
+
 	// don't precondition longer than charging duration
 	precondition = min(precondition, requiredDuration)
 
@@ -175,25 +180,6 @@ func (t *Planner) Plan(requiredDuration, precondition time.Duration, targetTime
 	// create plan unless only precond slots remaining
 	var plan api.Rates
 	if continuous {
-		// check if available tariff slots span is sufficient for sliding window algorithm
-		// verify that actual tariff data covers enough duration (may have gaps or start late)
-		if len(rates) > 0 {
-			start := rates[0].Start
-			if start.Before(now) {
-				start = now
-			}
-
-			end := rates[len(rates)-1].End
-			if end.After(targetTime) {
-				end = targetTime
-			}
-
-			// available window too small for sliding window - charge continuously from now to target
-			if end.Sub(start) < requiredDuration {
-				return continuousPlan(append(rates, precond...), now, targetTime.Add(precondition))
-			}
-		}
-
 		// find cheapest continuous window
 		plan = findContinuousWindow(rates, requiredDuration, targetTime)
 	} else {
diff --git a/core/planner/planner_continuous_test.go b/core/planner/planner_continuous_test.go
index ff383ea874c..4f9c97fc28a 100644
--- a/core/planner/planner_continuous_test.go
+++ b/core/planner/planner_continuous_test.go
@@ -548,8 +548,8 @@ func TestContinuous_StartBeforeRates(t *testing.T) {
 
 // TestContinuous_StartBeforeRatesInsufficientTime tests that when current time
 // is before the first available rate AND there's not enough time after rates
-// start to complete charging before target, the planner starts charging as soon
-// as rates become available (best effort approach)
+// start to complete charging before target, the planner starts at the latest
+// possible time to reach target (best effort approach)
 func TestContinuous_StartBeforeRatesInsufficientTime(t *testing.T) {
 	now := time.Date(1970, time.January, 1, 0, 0, 0, 0, time.UTC)
 	c := clock.NewMock()
@@ -581,8 +581,8 @@ func TestContinuous_StartBeforeRatesInsufficientTime(t *testing.T) {
 
 	require.NotEmpty(t, plan, "plan should not be empty")
 
-	// Best effort: start immediately to maximize charging time
-	assert.Equal(t, now, plan[0].Start, "should start immediately")
+	// Best effort: start at latest possible time to maximize charging time
+	assert.Equal(t, now.Add(1*time.Hour), plan[0].Start, "should start at latest possible time")
 	assert.Equal(t, 0.0, plan[0].Value, "gap-filling slot before rates has no price")
 }
 
diff --git a/core/planner/planner_test.go b/core/planner/planner_test.go
index 011d7a4734c..e6db1640e01 100644
--- a/core/planner/planner_test.go
+++ b/core/planner/planner_test.go
@@ -497,9 +497,8 @@ func TestStartBeforeRates(t *testing.T) {
 }
 
 // TestStartBeforeRatesInsufficientTime tests that when current time
-// is before the first available rate AND there's not enough time after rates
-// start to complete charging before target, the planner starts charging as soon
-// as rates become available (best effort approach)
+// is before the first available rate AND there's not enough rate coverage
+// to complete charging, the planner falls back to simplePlan (ignoring rates)
 func TestStartBeforeRatesInsufficientTime(t *testing.T) {
 	now := time.Date(1970, time.January, 1, 0, 0, 0, 0, time.UTC)
 	c := clock.NewMock()
@@ -525,13 +524,32 @@ func TestStartBeforeRatesInsufficientTime(t *testing.T) {
 	}
 
 	targetTime := now.Add(4 * time.Hour)
-	requiredDuration := 3 * time.Hour // Need 3h but only 2h available after rates start
+	requiredDuration := 3 * time.Hour // Need 3h but only 2h rate coverage
 
 	plan := planner.Plan(requiredDuration, 0, targetTime, false) // dispersed mode
 
-	require.NotEmpty(t, plan, "plan should not be empty - starts when rates become available")
+	require.NotEmpty(t, plan, "plan should not be empty")
+
+	// Insufficient rate coverage: fall back to simplePlan starting at latestStart
+	assert.Equal(t, now.Add(1*time.Hour), plan[0].Start, "should start at latestStart (target - required)")
+	assert.Equal(t, 0.0, plan[0].Value, "simplePlan has no price info")
+}
+
+// TestEmptyRatesAfterClamping tests fallback to simplePlan when no rates cover [now, targetTime]
+func TestEmptyRatesAfterClamping(t *testing.T) {
+	c := clock.NewMock()
+	ctrl := gomock.NewController(t)
+
+	trf := api.NewMockTariff(ctrl)
+	trf.EXPECT().Rates().AnyTimes().Return(rates([]float64{0.20}, c.Now().Add(3*time.Hour), time.Hour), nil)
+
+	p := &Planner{
+		log:    util.NewLogger("test"),
+		clock:  c,
+		tariff: trf,
+	}
 
-	// Best effort: start as soon as rates are available
-	assert.Equal(t, now.Add(2*time.Hour), plan[0].Start, "should start at first available rate")
-	assert.Equal(t, 0.10, plan[0].Value, "should use first available rate price")
+	plan := p.Plan(time.Hour, 0, c.Now().Add(90*time.Minute), false)
+	require.Len(t, plan, 1)
+	assert.Equal(t, c.Now().Add(30*time.Minute), plan[0].Start)
 }