diff --git a/app/models/client.rb b/app/models/client.rb
index bb674c5..842921b 100644
--- a/app/models/client.rb
+++ b/app/models/client.rb
@@ -10,15 +10,12 @@
 #
 
 class Client < ActiveRecord::Base
+  has_many :issued_transactions, as: :issuer, class_name: 'Transaction'
   before_create :generate_key
 
   validates :name, presence: true, uniqueness: true
   validates :key, presence: true, uniqueness: true
 
-  def transactions
-    Transaction.where(origin: name)
-  end
-
   private
   def generate_key
     self.key = SecureRandom.base64(16) unless self.key
diff --git a/app/models/transaction.rb b/app/models/transaction.rb
index 2e6f346..cadbe06 100644
--- a/app/models/transaction.rb
+++ b/app/models/transaction.rb
@@ -15,6 +15,7 @@
 class Transaction < ActiveRecord::Base
   belongs_to :debtor, class_name: 'User'
   belongs_to :creditor, class_name: 'User'
+  belongs_to :issuer, polymorphic: true
 
   after_save    :recalculate_balances
   after_destroy :recalculate_balances
@@ -22,10 +23,6 @@ class Transaction < ActiveRecord::Base
   validates :amount, numericality: { greater_than: 0 }
   validate :different_debtor_creditor
 
-  def client
-    Client.find_by name: origin
-  end
-
   private
 
   def recalculate_balances
@@ -34,6 +31,8 @@ class Transaction < ActiveRecord::Base
   end
 
   def different_debtor_creditor
-    self.errors.add :base, "Can't write money to yourself" if self.debtor == self.creditor
+    if self.debtor == self.creditor
+      self.errors.add :base, "Can't write money to yourself"
+    end
   end
 end
diff --git a/app/models/user.rb b/app/models/user.rb
index 8a318e9..c5886cf 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -17,6 +17,8 @@ class User < ActiveRecord::Base
   has_many :outgoing_transactions,
     class_name: 'Transaction', foreign_key: 'debtor_id'
 
+  has_many :issued_transactions, as: :issuer, class_name: 'Transaction'
+
   validates :name, presence: true, uniqueness: true
 
   def transactions
diff --git a/db/migrate/20150908091546_create_transactions.rb b/db/migrate/20150908091546_create_transactions.rb
index dda51f7..d1e83c4 100644
--- a/db/migrate/20150908091546_create_transactions.rb
+++ b/db/migrate/20150908091546_create_transactions.rb
@@ -3,8 +3,8 @@ class CreateTransactions < ActiveRecord::Migration
     create_table :transactions do |t|
       t.references :debtor, index: true, null: false
       t.references :creditor, index: true, null: false
+      t.references :issuer, polymorphic: true, index: true, null: false
       t.integer :amount, null: false, default: 0
-      t.string :origin, null: false
       t.string :message
 
       t.timestamps null: false
diff --git a/db/schema.rb b/db/schema.rb
index b4292bf..f6bf104 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -26,8 +26,9 @@ ActiveRecord::Schema.define(version: 20150908092731) do
   create_table "transactions", force: :cascade do |t|
     t.integer  "debtor_id",               null: false
     t.integer  "creditor_id",             null: false
+    t.integer  "issuer_id",               null: false
+    t.string   "issuer_type",             null: false
     t.integer  "amount",      default: 0, null: false
-    t.string   "origin",                  null: false
     t.string   "message"
     t.datetime "created_at",              null: false
     t.datetime "updated_at",              null: false
@@ -35,6 +36,7 @@ ActiveRecord::Schema.define(version: 20150908092731) do
 
   add_index "transactions", ["creditor_id"], name: "index_transactions_on_creditor_id"
   add_index "transactions", ["debtor_id"], name: "index_transactions_on_debtor_id"
+  add_index "transactions", ["issuer_type", "issuer_id"], name: "index_transactions_on_issuer_type_and_issuer_id"
 
   create_table "users", force: :cascade do |t|
     t.string   "name"