diff --git a/internal/x/paychan/README.md b/internal/x/paychan/README.md
index 7cb74683..80a3492e 100644
--- a/internal/x/paychan/README.md
+++ b/internal/x/paychan/README.md
@@ -12,8 +12,8 @@ Simplifications:
  - refactor queue into one object
  - Do all the small functions need to be methods on the keeper or can they just be floating around?
  - Tidy up - standardise var names, method descriptions, heading comments
- - is having all the get functions return a bool if not found reasonable?
  - any problem in signing your own address?
  - Gas
  - Codespace
  - find nicer name for payouts
+ - tags - return channel id
diff --git a/internal/x/paychan/endblocker_test.go b/internal/x/paychan/endblocker_test.go
index 079cb7e7..d6e1d5dd 100644
--- a/internal/x/paychan/endblocker_test.go
+++ b/internal/x/paychan/endblocker_test.go
@@ -31,7 +31,6 @@ func TestEndBlocker(t *testing.T) {
 	update := Update{
 		ChannelID: channelID,
 		Payouts:   payouts,
-		Sequence:  0,
 		Sigs:      [1]crypto.Signature{},
 	}
 	sUpdate := SubmittedUpdate{
diff --git a/internal/x/paychan/keeper.go b/internal/x/paychan/keeper.go
index d8520fb1..02c24e29 100644
--- a/internal/x/paychan/keeper.go
+++ b/internal/x/paychan/keeper.go
@@ -97,11 +97,18 @@ func (k Keeper) InitCloseChannelBySender(ctx sdk.Context, update Update) (sdk.Ta
 	}
 	if q.Contains(update.ChannelID) {
 		// Someone has previously tried to update channel
-		existingSUpdate, found := k.getSubmittedUpdate(ctx, update.ChannelID)
-		if !found {
-			panic("can't find element in queue that should exist")
-		}
-		k.addToSubmittedUpdatesQueue(ctx, k.applyNewUpdate(existingSUpdate, update))
+		// In bidirectional channels the new update is compared against existing and replaces it if it has a higher sequence number.
+
+		// existingSUpdate, found := k.getSubmittedUpdate(ctx, update.ChannelID)
+		// if !found {
+		// 	panic("can't find element in queue that should exist")
+		// }
+		// k.addToSubmittedUpdatesQueue(ctx, k.applyNewUpdate(existingSUpdate, update))
+
+		// However in unidirectional case, only the sender can close a channel this way. No clear need for them to be able to submit an update replacing a previous one they sent, so don't allow it.
+		// TODO tags
+		// TODO custom errors return sdk.EmptyTags(), sdk.NewError("Sender can't submit an update for channel if one has already been submitted.")
+		panic("Sender can't submit an update for channel if one has already been submitted.")
 	} else {
 		// No one has tried to update channel
 		submittedUpdate := SubmittedUpdate{
@@ -136,21 +143,22 @@ func (k Keeper) CloseChannelByReceiver(ctx sdk.Context, update Update) (sdk.Tags
 
 // Main function that compare updates against each other.
 // Pure function
-func (k Keeper) applyNewUpdate(existingSUpdate SubmittedUpdate, proposedUpdate Update) SubmittedUpdate {
-	var returnUpdate SubmittedUpdate
+// Not needed in unidirectional case.
+// func (k Keeper) applyNewUpdate(existingSUpdate SubmittedUpdate, proposedUpdate Update) SubmittedUpdate {
+// 	var returnUpdate SubmittedUpdate
 
-	if existingSUpdate.Sequence > proposedUpdate.Sequence {
-		// update accepted
-		returnUpdate = SubmittedUpdate{
-			Update:        proposedUpdate,
-			ExecutionTime: existingSUpdate.ExecutionTime,
-		}
-	} else {
-		// update rejected
-		returnUpdate = existingSUpdate
-	}
-	return returnUpdate
-}
+// 	if existingSUpdate.Sequence > proposedUpdate.Sequence {
+// 		// update accepted
+// 		returnUpdate = SubmittedUpdate{
+// 			Update:        proposedUpdate,
+// 			ExecutionTime: existingSUpdate.ExecutionTime, // FIXME any new update proposal should be subject to full dispute period from submission
+// 		}
+// 	} else {
+// 		// update rejected
+// 		returnUpdate = existingSUpdate
+// 	}
+// 	return returnUpdate
+// }
 
 // unsafe close channel - doesn't check if update matches existing channel TODO make safer?
 func (k Keeper) closeChannel(ctx sdk.Context, update Update) (sdk.Tags, sdk.Error) {
diff --git a/internal/x/paychan/keeper_test.go b/internal/x/paychan/keeper_test.go
index 392f24a8..9fd59a87 100644
--- a/internal/x/paychan/keeper_test.go
+++ b/internal/x/paychan/keeper_test.go
@@ -70,7 +70,6 @@ func TestKeeper(t *testing.T) {
 		update := Update{
 			ChannelID: channelID,
 			Payouts:   payouts,
-			Sequence:  0,
 			Sigs:      [1]crypto.Signature{},
 		}
 		// Set empty submittedUpdatesQueue TODO work out proper genesis initialisation
@@ -118,7 +117,6 @@ func TestKeeper(t *testing.T) {
 		update := Update{
 			ChannelID: channelID,
 			Payouts:   payouts,
-			Sequence:  0,
 			Sigs:      [1]crypto.Signature{},
 		}
 		// Set empty submittedUpdatesQueue TODO work out proper genesis initialisation
diff --git a/internal/x/paychan/types.go b/internal/x/paychan/types.go
index a93454e3..3ed695b9 100644
--- a/internal/x/paychan/types.go
+++ b/internal/x/paychan/types.go
@@ -23,8 +23,8 @@ type ChannelID int64 // TODO should this be positive only
 type Update struct {
 	ChannelID ChannelID
 	Payouts   Payouts //map[string]sdk.Coins // map of bech32 addresses to coins
-	Sequence  int64
-	Sigs      [1]crypto.Signature // only sender needs to sign
+	//Sequence  int64 Not needed for unidirectional channels
+	Sigs [1]crypto.Signature // only sender needs to sign in unidirectional
 }
 type Payout struct {
 	Address sdk.AccAddress