diff --git a/codex/sales.nim b/codex/sales.nim
index 53b5860b..0f76f175 100644
--- a/codex/sales.nim
+++ b/codex/sales.nim
@@ -109,6 +109,7 @@ proc remove(sales: Sales, agent: SalesAgent) {.async.} =
 
 proc cleanUp(sales: Sales,
              agent: SalesAgent,
+             returnBytes: bool,
              processing: Future[void]) {.async.} =
 
   let data = agent.data
@@ -119,9 +120,19 @@ proc cleanUp(sales: Sales,
     reservationId = data.reservation.?id |? ReservationId.default,
     availabilityId = data.reservation.?availabilityId |? AvailabilityId.default
 
-  # TODO: return bytes that were used in the request back to the availability
-  # as well, which will require removing the bytes from disk (perhaps via
-  # setting blockTTL to -1 and then running block maintainer?)
+  # if reservation for the SalesAgent was not created, then it means
+  # that the cleanUp was called before the sales process really started, so
+  # there are not really any bytes to be returned
+  if returnBytes and request =? data.request and reservation =? data.reservation:
+    if returnErr =? (await sales.context.reservations.returnBytesToAvailability(
+                        reservation.availabilityId,
+                        reservation.id,
+                        request.ask.slotSize
+                      )).errorOption:
+          error "failure returning bytes",
+            error = returnErr.msg,
+            availabilityId = reservation.availabilityId,
+            bytes = request.ask.slotSize
 
   # delete reservation and return reservation bytes back to the availability
   if reservation =? data.reservation and
@@ -164,8 +175,8 @@ proc processSlot(sales: Sales, item: SlotQueueItem, done: Future[void]) =
     none StorageRequest
   )
 
-  agent.onCleanUp = proc {.async.} =
-    await sales.cleanUp(agent, done)
+  agent.onCleanUp = proc (returnBytes = false) {.async.} =
+    await sales.cleanUp(agent, returnBytes, done)
 
   agent.onFilled = some proc(request: StorageRequest, slotIndex: UInt256) =
     sales.filled(request, slotIndex, done)
@@ -229,9 +240,9 @@ proc load*(sales: Sales) {.async.} =
       slot.slotIndex,
       some slot.request)
 
-    agent.onCleanUp = proc {.async.} =
+    agent.onCleanUp = proc(returnBytes = false) {.async.} =
       let done = newFuture[void]("onCleanUp_Dummy")
-      await sales.cleanUp(agent, done)
+      await sales.cleanUp(agent, returnBytes, done)
       await done # completed in sales.cleanUp
 
     agent.start(SaleUnknown())
diff --git a/codex/sales/reservations.nim b/codex/sales/reservations.nim
index 001d6a5a..611c1ad6 100644
--- a/codex/sales/reservations.nim
+++ b/codex/sales/reservations.nim
@@ -359,6 +359,58 @@ proc createReservation*(
 
   return success(reservation)
 
+proc returnBytesToAvailability*(
+  self: Reservations,
+  availabilityId: AvailabilityId,
+  reservationId: ReservationId,
+  bytes: UInt256): Future[?!void] {.async.} =
+
+  logScope:
+    reservationId
+    availabilityId
+
+
+  without key =? key(reservationId, availabilityId), error:
+    return failure(error)
+
+  without var reservation =? (await self.get(key, Reservation)), error:
+    return failure(error)
+
+  # We are ignoring bytes that are still present in the Reservation because
+  # they will be returned to Availability through `deleteReservation`.
+  let bytesToBeReturned = bytes - reservation.size
+
+  if bytesToBeReturned == 0:
+    trace "No bytes are returned", requestSizeBytes = bytes, returningBytes = bytesToBeReturned
+    return success()
+
+  trace "Returning bytes", requestSizeBytes = bytes, returningBytes = bytesToBeReturned
+
+  # First lets see if we can re-reserve the bytes, if the Repo's quota
+  # is depleted then we will fail-fast as there is nothing to be done atm.
+  if reserveErr =? (await self.repo.reserve(bytesToBeReturned.truncate(uint))).errorOption:
+    return failure(reserveErr.toErr(ReserveFailedError))
+
+  without availabilityKey =? availabilityId.key, error:
+    return failure(error)
+
+  without var availability =? await self.get(availabilityKey, Availability), error:
+    return failure(error)
+
+  availability.size += bytesToBeReturned
+
+  # Update availability with returned size
+  if updateErr =? (await self.update(availability)).errorOption:
+
+    trace "Rolling back returning bytes"
+    if rollbackErr =? (await self.repo.release(bytesToBeReturned.truncate(uint))).errorOption:
+      rollbackErr.parent = updateErr
+      return failure(rollbackErr)
+
+    return failure(updateErr)
+
+  return success()
+
 proc release*(
   self: Reservations,
   reservationId: ReservationId,
diff --git a/codex/sales/salesagent.nim b/codex/sales/salesagent.nim
index b189650d..08d3ab0e 100644
--- a/codex/sales/salesagent.nim
+++ b/codex/sales/salesagent.nim
@@ -25,7 +25,7 @@ type
     onCleanUp*: OnCleanUp
     onFilled*: ?OnFilled
 
-  OnCleanUp* = proc: Future[void] {.gcsafe, upraises: [].}
+  OnCleanUp* = proc (returnBytes = false): Future[void] {.gcsafe, upraises: [].}
   OnFilled* = proc(request: StorageRequest,
                    slotIndex: UInt256) {.gcsafe, upraises: [].}
 
diff --git a/codex/sales/states/cancelled.nim b/codex/sales/states/cancelled.nim
index 3f0e2157..f1f75407 100644
--- a/codex/sales/states/cancelled.nim
+++ b/codex/sales/states/cancelled.nim
@@ -29,6 +29,6 @@ method run*(state: SaleCancelled, machine: Machine): Future[?State] {.async.} =
     onClear(request, data.slotIndex)
 
   if onCleanUp =? agent.onCleanUp:
-    await onCleanUp()
+    await onCleanUp(returnBytes = true)
 
   warn "Sale cancelled due to timeout",  requestId = $data.requestId, slotIndex = $data.slotIndex
diff --git a/codex/sales/states/errored.nim b/codex/sales/states/errored.nim
index c934be4b..59754eca 100644
--- a/codex/sales/states/errored.nim
+++ b/codex/sales/states/errored.nim
@@ -29,5 +29,5 @@ method run*(state: SaleErrored, machine: Machine): Future[?State] {.async.} =
     onClear(request, data.slotIndex)
 
   if onCleanUp =? agent.onCleanUp:
-    await onCleanUp()
+    await onCleanUp(returnBytes = true)
 
diff --git a/tests/codex/sales/testreservations.nim b/tests/codex/sales/testreservations.nim
index 3bfee998..a6ab1b26 100644
--- a/tests/codex/sales/testreservations.nim
+++ b/tests/codex/sales/testreservations.nim
@@ -175,6 +175,24 @@ asyncchecksuite "Reservations module":
     let updated = !(await reservations.get(key, Availability))
     check updated.size == orig
 
+  test "calling returnBytesToAvailability returns bytes back to availability":
+    let availability = createAvailability()
+    let reservation = createReservation(availability)
+    let orig = availability.size - reservation.size
+    let origQuota = repo.quotaReservedBytes
+    let returnedBytes = reservation.size + 200.u256
+
+    check isOk await reservations.returnBytesToAvailability(
+      reservation.availabilityId, reservation.id, returnedBytes
+    )
+
+    let key = availability.key.get
+    let updated = !(await reservations.get(key, Availability))
+
+    check updated.size > orig
+    check (updated.size - orig) == 200.u256
+    check (repo.quotaReservedBytes - origQuota) == 200
+
   test "reservation can be partially released":
     let availability = createAvailability()
     let reservation = createReservation(availability)
diff --git a/tests/codex/sales/testsales.nim b/tests/codex/sales/testsales.nim
index 7b47f375..6668b105 100644
--- a/tests/codex/sales/testsales.nim
+++ b/tests/codex/sales/testsales.nim
@@ -149,6 +149,7 @@ asyncchecksuite "Sales":
 
     let me = await market.getSigner()
     market.activeSlots[me] = @[]
+    market.requestEnds[request.id] = request.expiry.toSecondsSince1970
 
     clock = MockClock.new()
     let repoDs = SQLiteDatastore.new(Memory).tryGet()
@@ -169,7 +170,6 @@ asyncchecksuite "Sales":
     sales.onProve = proc(slot: Slot, challenge: ProofChallenge): Future[seq[byte]] {.async.} =
       return proof
     await sales.start()
-    request.expiry = (clock.now() + 42).u256
     itemsProcessed = @[]
 
   teardown: