diff --git a/src/main/java/org/qortal/controller/tradebot/BitcoinACCTv1TradeBot.java b/src/main/java/org/qortal/controller/tradebot/BitcoinACCTv1TradeBot.java
index 60ca14b7..5af8aa45 100644
--- a/src/main/java/org/qortal/controller/tradebot/BitcoinACCTv1TradeBot.java
+++ b/src/main/java/org/qortal/controller/tradebot/BitcoinACCTv1TradeBot.java
@@ -387,32 +387,32 @@ public class BitcoinACCTv1TradeBot implements AcctTradeBot {
 				break;
 
 			case ALICE_WAITING_FOR_P2SH_A:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleAliceWaitingForP2shA(repository, tradeBotData, atData, tradeData);
 				break;
 
 			case BOB_WAITING_FOR_MESSAGE:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleBobWaitingForMessage(repository, tradeBotData, atData, tradeData);
 				break;
 
 			case ALICE_WAITING_FOR_AT_LOCK:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleAliceWaitingForAtLock(repository, tradeBotData, atData, tradeData);
 				break;
 
 			case BOB_WAITING_FOR_P2SH_B:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleBobWaitingForP2shB(repository, tradeBotData, atData, tradeData);
 				break;
 
 			case ALICE_WATCH_P2SH_B:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleAliceWatchingP2shB(repository, tradeBotData, atData, tradeData);
 				break;
 
 			case BOB_WAITING_FOR_AT_REDEEM:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleBobWaitingForAtRedeem(repository, tradeBotData, atData, tradeData);
 				break;
 
@@ -421,12 +421,12 @@ public class BitcoinACCTv1TradeBot implements AcctTradeBot {
 				break;
 
 			case ALICE_REFUNDING_B:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleAliceRefundingP2shB(repository, tradeBotData, atData, tradeData);
 				break;
 
 			case ALICE_REFUNDING_A:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleAliceRefundingP2shA(repository, tradeBotData, atData, tradeData);
 				break;
 
diff --git a/src/main/java/org/qortal/controller/tradebot/LitecoinACCTv1TradeBot.java b/src/main/java/org/qortal/controller/tradebot/LitecoinACCTv1TradeBot.java
index 5fc8b3ab..b87b2bcf 100644
--- a/src/main/java/org/qortal/controller/tradebot/LitecoinACCTv1TradeBot.java
+++ b/src/main/java/org/qortal/controller/tradebot/LitecoinACCTv1TradeBot.java
@@ -384,17 +384,17 @@ public class LitecoinACCTv1TradeBot implements AcctTradeBot {
 				break;
 
 			case BOB_WAITING_FOR_MESSAGE:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleBobWaitingForMessage(repository, tradeBotData, atData, tradeData);
 				break;
 
 			case ALICE_WAITING_FOR_AT_LOCK:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleAliceWaitingForAtLock(repository, tradeBotData, atData, tradeData);
 				break;
 
 			case BOB_WAITING_FOR_AT_REDEEM:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleBobWaitingForAtRedeem(repository, tradeBotData, atData, tradeData);
 				break;
 
@@ -403,7 +403,7 @@ public class LitecoinACCTv1TradeBot implements AcctTradeBot {
 				break;
 
 			case ALICE_REFUNDING_A:
-				TradeBot.getInstance().updatePresence(repository, tradeBotData);
+				TradeBot.getInstance().updatePresence(repository, tradeBotData, tradeData);
 				handleAliceRefundingP2shA(repository, tradeBotData, atData, tradeData);
 				break;
 
diff --git a/src/main/java/org/qortal/controller/tradebot/TradeBot.java b/src/main/java/org/qortal/controller/tradebot/TradeBot.java
index b37d3b76..d98e8fa7 100644
--- a/src/main/java/org/qortal/controller/tradebot/TradeBot.java
+++ b/src/main/java/org/qortal/controller/tradebot/TradeBot.java
@@ -307,20 +307,32 @@ public class TradeBot implements Listener {
 	}
 
 	// PRESENCE-related
-	/*package*/ void updatePresence(Repository repository, TradeBotData tradeBotData) throws DataException {
-		String key = tradeBotData.getAtAddress();
+	/*package*/ void updatePresence(Repository repository, TradeBotData tradeBotData, CrossChainTradeData tradeData)
+			throws DataException {
+		String atAddress = tradeBotData.getAtAddress();
+
+		PrivateKeyAccount tradeNativeAccount = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
+		String signerAddress = tradeNativeAccount.getAddress();
+
+		/*
+		 * There's no point in Alice trying to build a PRESENCE transaction
+		 * for an AT that isn't locked to her, as other peers won't be able
+		 * to validate the PRESENCE transaction as signing public key won't
+		 * be visible.
+		 */
+		if (!signerAddress.equals(tradeData.qortalCreatorTradeAddress) && !signerAddress.equals(tradeData.qortalPartnerAddress))
+			// Signer is neither Bob, nor Alice, or trade not yet locked to Alice
+			return;
 
 		long now = NTP.getTime();
 		long threshold = now - PresenceType.TRADE_BOT.getLifetime();
 
-		long timestamp = presenceTimestampsByAtAddress.compute(key, (k, v) -> (v == null || v < threshold) ? now : v);
+		long timestamp = presenceTimestampsByAtAddress.compute(atAddress, (k, v) -> (v == null || v < threshold) ? now : v);
 
 		// If timestamp hasn't been updated then nothing to do
 		if (timestamp != now)
 			return;
 
-		PrivateKeyAccount tradeNativeAccount = new PrivateKeyAccount(repository, tradeBotData.getTradePrivateKey());
-
 		int txGroupId = Group.NO_GROUP;
 		byte[] reference = new byte[TransactionTransformer.SIGNATURE_LENGTH];
 		byte[] creatorPublicKey = tradeNativeAccount.getPublicKey();
diff --git a/src/main/java/org/qortal/transaction/PresenceTransaction.java b/src/main/java/org/qortal/transaction/PresenceTransaction.java
index e5b96661..772928e9 100644
--- a/src/main/java/org/qortal/transaction/PresenceTransaction.java
+++ b/src/main/java/org/qortal/transaction/PresenceTransaction.java
@@ -168,15 +168,15 @@ public class PresenceTransaction extends Transaction {
 		if (!Crypto.verify(this.transactionData.getCreatorPublicKey(), timestampSignature, timestampBytes))
 			return ValidationResult.INVALID_TIMESTAMP_SIGNATURE;
 
-		// Check signer is known trade address
-		String signerAddress = Crypto.toAddress(this.transactionData.getCreatorPublicKey());
-
 		Map<ByteArray, Supplier<ACCT>> acctSuppliersByCodeHash = SupportedBlockchain.getAcctMap();
 		Set<ByteArray> codeHashes = acctSuppliersByCodeHash.keySet();
 		boolean isExecutable = true;
 
 		List<ATData> atsData = repository.getATRepository().getAllATsByFunctionality(codeHashes, isExecutable);
 
+		// Convert signer's public key to address form
+		String signerAddress = Crypto.toAddress(this.transactionData.getCreatorPublicKey());
+
 		for (ATData atData : atsData) {
 			ByteArray atCodeHash = new ByteArray(atData.getCodeHash());
 			Supplier<ACCT> acctSupplier = acctSuppliersByCodeHash.get(atCodeHash);
@@ -185,7 +185,12 @@ public class PresenceTransaction extends Transaction {
 
 			CrossChainTradeData crossChainTradeData = acctSupplier.get().populateTradeData(repository, atData);
 
-			if (crossChainTradeData.qortalCreatorTradeAddress.equals(signerAddress))
+			// OK if signer's public key (in address form) matches Bob's trade public key (in address form)
+			if (signerAddress.equals(crossChainTradeData.qortalCreatorTradeAddress))
+				return ValidationResult.OK;
+
+			// OK if signer's public key (in address form) matches Alice's trade public key (in address form)
+			if (signerAddress.equals(crossChainTradeData.qortalPartnerAddress))
 				return ValidationResult.OK;
 		}