diff --git a/parity/rpc_apis.rs b/parity/rpc_apis.rs
index be9dbdeb1..a5bc1e154 100644
--- a/parity/rpc_apis.rs
+++ b/parity/rpc_apis.rs
@@ -15,8 +15,7 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 use std::cmp::PartialEq;
-use std::collections::BTreeMap;
-use std::collections::HashSet;
+use std::collections::{BTreeMap, HashSet};
 use std::str::FromStr;
 use std::sync::{Arc, Weak};
 
diff --git a/rpc/src/v1/helpers/dispatch.rs b/rpc/src/v1/helpers/dispatch.rs
index c556226b5..35e16f573 100644
--- a/rpc/src/v1/helpers/dispatch.rs
+++ b/rpc/src/v1/helpers/dispatch.rs
@@ -92,7 +92,11 @@ pub struct FullDispatcher<C, M> {
 
 impl<C, M> FullDispatcher<C, M> {
 	/// Create a `FullDispatcher` from Arc references to a client and miner.
-	pub fn new(client: Arc<C>, miner: Arc<M>, nonces: Arc<Mutex<nonce::Reservations>>) -> Self {
+	pub fn new(
+		client: Arc<C>,
+		miner: Arc<M>,
+		nonces: Arc<Mutex<nonce::Reservations>>,
+	) -> Self {
 		FullDispatcher {
 			client,
 			miner,
@@ -162,7 +166,8 @@ impl<C: MiningBlockChainClient, M: MinerService> Dispatcher for FullDispatcher<C
 		}
 
 		let state = self.state_nonce(&filled.from);
-		let reserved = self.nonces.lock().reserve_nonce(state);
+		let reserved = self.nonces.lock().reserve(filled.from, state);
+
 		Box::new(ProspectiveSigner::new(accounts, filled, chain_id, reserved, password))
 	}
 
@@ -382,7 +387,8 @@ impl Dispatcher for LightDispatcher {
 		Box::new(self.next_nonce(filled.from)
 			.map_err(|_| errors::no_light_peers())
 			.and_then(move |nonce| {
-				let reserved = nonces.lock().reserve_nonce(nonce);
+				let reserved = nonces.lock().reserve(filled.from, nonce);
+
 				ProspectiveSigner::new(accounts, filled, chain_id, reserved, password)
 			}))
 	}
diff --git a/rpc/src/v1/helpers/nonce.rs b/rpc/src/v1/helpers/nonce.rs
index a048d9a87..30ad15211 100644
--- a/rpc/src/v1/helpers/nonce.rs
+++ b/rpc/src/v1/helpers/nonce.rs
@@ -15,35 +15,81 @@
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
 use std::{cmp, mem};
+use std::collections::HashMap;
 use std::sync::{atomic, Arc};
-use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::{AtomicBool, AtomicUsize};
 
 use bigint::prelude::U256;
 use futures::{Future, future, Poll, Async};
 use futures::future::Either;
 use futures::sync::oneshot;
 use futures_cpupool::CpuPool;
+use util::Address;
 
-/// Manages currently reserved and prospective nonces.
+/// Manages currently reserved and prospective nonces
+/// for multiple senders.
 #[derive(Debug)]
 pub struct Reservations {
-	previous: Option<oneshot::Receiver<U256>>,
+	nonces: HashMap<Address, SenderReservations>,
 	pool: CpuPool,
-	prospective_value: U256,
-	dropped: Arc<AtomicUsize>,
 }
-
 impl Reservations {
+	/// A maximal number of reserved nonces in the hashmap
+	/// before we start clearing the unused ones.
+	const CLEAN_AT: usize = 512;
+
 	/// Create new nonces manager and spawn a single-threaded cpu pool
 	/// for progressing execution of dropped nonces.
 	pub fn new() -> Self {
 		Self::with_pool(CpuPool::new(1))
 	}
 
-	/// Create new nonces manager with given cpu pool.
+	/// Create new nonces manager with given cpupool.
 	pub fn with_pool(pool: CpuPool) -> Self {
 		Reservations {
+			nonces: Default::default(),
+			pool,
+		}
+	}
+
+	/// Reserve a nonce for particular address.
+	///
+	/// The reserved nonce cannot be smaller than the minimal nonce.
+	pub fn reserve(&mut self, sender: Address, minimal: U256) -> Reserved {
+		if self.nonces.len() + 1 > Self::CLEAN_AT {
+			self.nonces.retain(|_, v| !v.is_empty());
+		}
+
+		let pool = &self.pool;
+		self.nonces.entry(sender)
+			.or_insert_with(move || SenderReservations::with_pool(pool.clone()))
+			.reserve_nonce(minimal)
+	}
+}
+
+/// Manages currently reserved and prospective nonces.
+#[derive(Debug)]
+pub struct SenderReservations {
+	previous: Option<oneshot::Receiver<U256>>,
+	previous_ready: Arc<AtomicBool>,
+	pool: CpuPool,
+	prospective_value: U256,
+	dropped: Arc<AtomicUsize>,
+}
+
+impl SenderReservations {
+	/// Create new nonces manager and spawn a single-threaded cpu pool
+	/// for progressing execution of dropped nonces.
+	#[cfg(test)]
+	pub fn new() -> Self {
+		Self::with_pool(CpuPool::new(1))
+	}
+
+	/// Create new nonces manager with given cpu pool.
+	pub fn with_pool(pool: CpuPool) -> Self {
+		SenderReservations {
 			previous: None,
+			previous_ready: Arc::new(AtomicBool::new(true)),
 			pool,
 			prospective_value: Default::default(),
 			dropped: Default::default(),
@@ -64,12 +110,15 @@ impl Reservations {
 
 		let (next, rx) = oneshot::channel();
 		let next = Some(next);
+		let next_sent = Arc::new(AtomicBool::default());
 		let pool = self.pool.clone();
 		let dropped = self.dropped.clone();
+		self.previous_ready = next_sent.clone();
 		match mem::replace(&mut self.previous, Some(rx)) {
 			Some(previous) => Reserved {
 				previous: Either::A(previous),
 				next,
+				next_sent,
 				minimal,
 				prospective_value,
 				pool,
@@ -78,6 +127,7 @@ impl Reservations {
 			None => Reserved {
 				previous: Either::B(future::ok(minimal)),
 				next,
+				next_sent,
 				minimal,
 				prospective_value,
 				pool,
@@ -85,6 +135,11 @@ impl Reservations {
 			},
 		}
 	}
+
+	/// Returns true if there are no reserved nonces.
+	pub fn is_empty(&self) -> bool {
+		self.previous_ready.load(atomic::Ordering::SeqCst)
+	}
 }
 
 /// Represents a future nonce.
@@ -92,9 +147,10 @@ impl Reservations {
 pub struct Reserved {
 	previous: Either<
 		oneshot::Receiver<U256>,
-		future::FutureResult<U256, oneshot::Canceled>
+		future::FutureResult<U256, oneshot::Canceled>,
 	>,
 	next: Option<oneshot::Sender<U256>>,
+	next_sent: Arc<AtomicBool>,
 	minimal: U256,
 	prospective_value: U256,
 	pool: CpuPool,
@@ -128,6 +184,7 @@ impl Future for Reserved {
 			value,
 			matches_prospective,
 			next: self.next.take(),
+			next_sent: self.next_sent.clone(),
 			dropped: self.dropped.clone(),
 		}))
 	}
@@ -136,10 +193,12 @@ impl Future for Reserved {
 impl Drop for Reserved {
 	fn drop(&mut self) {
 		if let Some(next) = self.next.take() {
+			let next_sent = self.next_sent.clone();
 			self.dropped.fetch_add(1, atomic::Ordering::SeqCst);
 			// If Reserved is dropped just pipe previous and next together.
 			let previous = mem::replace(&mut self.previous, Either::B(future::ok(U256::default())));
-			self.pool.spawn(previous.map(|nonce| {
+			self.pool.spawn(previous.map(move |nonce| {
+				next_sent.store(true, atomic::Ordering::SeqCst);
 				next.send(nonce).expect(Ready::RECV_PROOF)
 			})).forget()
 		}
@@ -156,6 +215,7 @@ pub struct Ready {
 	value: U256,
 	matches_prospective: bool,
 	next: Option<oneshot::Sender<U256>>,
+	next_sent: Arc<AtomicBool>,
 	dropped: Arc<AtomicUsize>,
 }
 
@@ -176,15 +236,17 @@ impl Ready {
 	/// Make sure to call that method after this nonce has been consumed.
 	pub fn mark_used(mut self) {
 		let next = self.next.take().expect("Nonce can be marked as used only once; qed");
+		self.next_sent.store(true, atomic::Ordering::SeqCst);
 		next.send(self.value + 1.into()).expect(Self::RECV_PROOF);
 	}
 }
 
 impl Drop for Ready {
 	fn drop(&mut self) {
-		if let Some(send) = self.next.take() {
+		if let Some(next) = self.next.take() {
 			self.dropped.fetch_add(1, atomic::Ordering::SeqCst);
-			send.send(self.value).expect(Self::RECV_PROOF);
+			self.next_sent.store(true, atomic::Ordering::SeqCst);
+			next.send(self.value).expect(Self::RECV_PROOF);
 		}
 	}
 }
@@ -195,12 +257,14 @@ mod tests {
 
 	#[test]
 	fn should_reserve_a_set_of_nonces_and_resolve_them() {
-		let mut nonces = Reservations::new();
+		let mut nonces = SenderReservations::new();
 
+		assert!(nonces.is_empty());
 		let n1 = nonces.reserve_nonce(5.into());
 		let n2 = nonces.reserve_nonce(5.into());
 		let n3 = nonces.reserve_nonce(5.into());
 		let n4 = nonces.reserve_nonce(5.into());
+		assert!(!nonces.is_empty());
 
 		// Check first nonce
 		let r = n1.wait().unwrap();
@@ -234,11 +298,13 @@ mod tests {
 		assert_eq!(r.value(), &U256::from(10));
 		assert!(r.matches_prospective());
 		r.mark_used();
+
+		assert!(nonces.is_empty());
 	}
 
 	#[test]
 	fn should_return_prospective_nonce() {
-		let mut nonces = Reservations::new();
+		let mut nonces = SenderReservations::new();
 
 		let n1 = nonces.reserve_nonce(5.into());
 		let n2 = nonces.reserve_nonce(5.into());