diff --git a/ledger/deltas.go b/ledger/deltas.go
new file mode 100644
index 0000000..61d1848
--- /dev/null
+++ b/ledger/deltas.go
@@ -0,0 +1,28 @@
+package ledger
+
+type Deltas []Delta
+
+func (deltas Deltas) Like(like ...Like) Deltas {
+	result := make(Deltas, 0, len(deltas))
+	for i := range deltas {
+		if likes(like).all(deltas[i]) {
+			result = append(result, deltas[i])
+		}
+	}
+	return result
+}
+
+func (deltas Deltas) Balances() (map[string]map[Currency]float64, error) {
+	result := make(map[string]map[Currency]float64)
+	for _, delta := range deltas {
+		if _, ok := result[delta.Account]; !ok {
+			result[delta.Account] = make(map[Currency]float64)
+		}
+		if _, ok := result[delta.Account][delta.Currency]; !ok {
+			result[delta.Account][delta.Currency] = 0
+		}
+		result[delta.Account][delta.Currency] += delta.Value
+	}
+
+	return result, nil
+}
diff --git a/ledger/file.go b/ledger/file.go
index e3ba278..da48f8e 100644
--- a/ledger/file.go
+++ b/ledger/file.go
@@ -12,27 +12,12 @@ func NewFiles(p string, q ...string) (Files, error) {
 	return f, err
 }
 
-func Balances(deltas []Delta) (map[string]map[Currency]float64, error) {
-	result := make(map[string]map[Currency]float64)
-	for _, delta := range deltas {
-		if _, ok := result[delta.Account]; !ok {
-			result[delta.Account] = make(map[Currency]float64)
-		}
-		if _, ok := result[delta.Account][delta.Currency]; !ok {
-			result[delta.Account][delta.Currency] = 0
-		}
-		result[delta.Account][delta.Currency] += delta.Value
-	}
-
-	return result, nil
-}
-
-func (files Files) Deltas(like ...Like) ([]Delta, error) {
+func (files Files) Deltas(like ...Like) (Deltas, error) {
 	transactions, err := files.transactions()
 	if err != nil {
 		return nil, err
 	}
-	result := make([]Delta, 0, len(transactions)*2)
+	result := make(Deltas, 0, len(transactions)*2)
 	for _, transaction := range transactions {
 		sums := map[string]float64{}
 		for _, acc := range transaction.recipients {
@@ -44,9 +29,7 @@ func (files Files) Deltas(like ...Like) ([]Delta, error) {
 				acc.value,
 				acc.currency,
 			)
-			if likes(like).all(delta) {
-				result = append(result, delta)
-			}
+			result = append(result, delta)
 		}
 		for currency, value := range sums {
 			if value == 0 {
@@ -62,10 +45,8 @@ func (files Files) Deltas(like ...Like) ([]Delta, error) {
 				-1.0*value,
 				currency,
 			)
-			if likes(like).all(delta) {
-				result = append(result, delta)
-			}
+			result = append(result, delta)
 		}
 	}
-	return result, nil
+	return result.Like(like...), nil
 }
diff --git a/ledger/file_test.go b/ledger/file_test.go
index a43633d..3d867a3 100644
--- a/ledger/file_test.go
+++ b/ledger/file_test.go
@@ -36,7 +36,7 @@ func TestFileTestdata(t *testing.T) {
 					t.Fatal(err)
 				}
 
-				balances, err := Balances(deltas)
+				balances, err := deltas.Balances()
 				if err != nil {
 					t.Fatal(err)
 				}
@@ -51,7 +51,7 @@ func TestFileTestdata(t *testing.T) {
 					t.Fatal(err)
 				}
 
-				balances, err := Balances(deltas)
+				balances, err := deltas.Balances()
 				if err != nil {
 					t.Fatal(err)
 				}