diff --git a/README b/README
index 607bd78e7..62ae63565 100644
--- a/README
+++ b/README
@@ -1 +1,10 @@
-Rating system for telecom providers.
+Rating system designed to be used in VoIP Carriers World.
+
+Features
+- Fast RatingEngine, holds all rating information into memory
+- Unlimited spanned timebased rating: considers both ActiveFrom/RateStartsAt
+- Unlimited rate profiles chanining for fallback
+- Rating Fields: ConnectFee, RateIn, RateOut
+- High accuracy rating: configurable to miliseconds
+- Flexible rates storage - plugin based rates loading
+- Flexibility to rate various information from the cdrs as rating subject.
diff --git a/timespans/userbudget.go b/timespans/userbudget.go
new file mode 100644
index 000000000..8a40716ba
--- /dev/null
+++ b/timespans/userbudget.go
@@ -0,0 +1,65 @@
+package timespans
+
+import (
+	"log"
+	"math"
+)
+
+/*
+Structure conatining information about user's credit (minutes, cents, sms...).'
+*/
+type UserBudget struct {
+	id                 string
+	minuteBuckets      []*MinuteBucket
+	credit             float64
+	smsCredit          int
+	tariffPlan         *TariffPlan
+	resetDayOfTheMonth int
+}
+
+/*
+Returns user's avaliable minutes for the specified destination
+*/
+func (ub *UserBudget) GetSecondsForPrefix(prefix string) (seconds int) {
+	if len(ub.minuteBuckets) == 0 {
+		log.Print("There are no minute buckets to check for user", ub.id)
+		return
+	}
+	bestBucket := ub.minuteBuckets[0]
+
+	for _, mb := range ub.minuteBuckets {
+		if mb.containsPrefix(prefix) && mb.priority > bestBucket.priority {
+			bestBucket = mb
+		}
+	}
+	seconds = bestBucket.seconds
+	if bestBucket.price > 0 {
+		seconds = int(math.Min(ub.credit/bestBucket.price, float64(seconds)))
+	}
+	return
+}
+
+type Destination struct {
+	id       string
+	prefixes []string
+}
+
+type MinuteBucket struct {
+	seconds     int
+	priority    int
+	price       float64
+	destination *Destination
+}
+
+func (mb *MinuteBucket) containsPrefix(prefix string) bool {
+	for _, p := range mb.destination.prefixes {
+		if prefix == p {
+			return true
+		}
+	}
+	return false
+}
+
+type TariffPlan struct {
+	minuteBuckets []*MinuteBucket
+}
diff --git a/timespans/userbudget_test.go b/timespans/userbudget_test.go
new file mode 100644
index 000000000..381b460ae
--- /dev/null
+++ b/timespans/userbudget_test.go
@@ -0,0 +1,51 @@
+package timespans
+
+import (
+	"testing"
+)
+
+var (
+	nationale = &Destination{id: "nationale", prefixes: []string{"0257", "0256", "0723"}}
+	retea     = &Destination{id: "retea", prefixes: []string{"0723", "0724"}}
+)
+
+func TestGetSeconds(t *testing.T) {
+	b1 := &MinuteBucket{seconds: 10, priority: 10, destination: nationale}
+	b2 := &MinuteBucket{seconds: 100, priority: 20, destination: retea}
+	tf1 := &TariffPlan{minuteBuckets: []*MinuteBucket{b1, b2}}
+
+	ub1 := &UserBudget{id: "rif", minuteBuckets: []*MinuteBucket{b1, b2}, credit: 200, tariffPlan: tf1, resetDayOfTheMonth: 10}
+	seconds := ub1.GetSecondsForPrefix("0723")
+	expected := 100
+	if seconds != expected {
+		t.Errorf("Expected %v was %v", expected, seconds)
+	}
+}
+
+func TestGetPricedSeconds(t *testing.T) {
+	b1 := &MinuteBucket{seconds: 10, price: 10, priority: 10, destination: nationale}
+	b2 := &MinuteBucket{seconds: 100, price: 1, priority: 20, destination: retea}
+	tf1 := &TariffPlan{minuteBuckets: []*MinuteBucket{b1, b2}}
+
+	ub1 := &UserBudget{id: "rif", minuteBuckets: []*MinuteBucket{b1, b2}, credit: 21, tariffPlan: tf1, resetDayOfTheMonth: 10}
+	seconds := ub1.GetSecondsForPrefix("0723")
+	expected := 21
+	if seconds != expected {
+		t.Errorf("Expected %v was %v", expected, seconds)
+	}
+}
+
+/*********************************** Benchmarks *******************************/
+
+func BenchmarkGetSecondForPrefix(b *testing.B) {
+	b.StopTimer()
+	b1 := &MinuteBucket{seconds: 10, price: 10, priority: 10, destination: nationale}
+	b2 := &MinuteBucket{seconds: 100, price: 1, priority: 20, destination: retea}
+	tf1 := &TariffPlan{minuteBuckets: []*MinuteBucket{b1, b2}}
+
+	ub1 := &UserBudget{id: "rif", minuteBuckets: []*MinuteBucket{b1, b2}, credit: 21, tariffPlan: tf1, resetDayOfTheMonth: 10}
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		ub1.GetSecondsForPrefix("0723")
+	}
+}