diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6859127e26..787bf0928e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,7 @@
 # Changelog
+## 1.2.13
+* Allow zero fees in `PATCH /transactions` request [#871](https://github.com/stellar/java-stellar-anchor-sdk/pull/871)
+
 ## 1.2.12
 * Don't set amount_out for indicative quote. [#823](https://github.com/stellar/java-stellar-anchor-sdk/pull/823)
 * Add docker-compose files to run e2e tests with containers
diff --git a/build.gradle.kts b/build.gradle.kts
index 1fc9a533af..a36f604f58 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -118,7 +118,7 @@ subprojects {
 
 allprojects {
   group = "org.stellar.anchor-sdk"
-  version = "1.2.12"
+  version = "1.2.13"
 
   tasks.jar {
     manifest {
diff --git a/core/src/main/java/org/stellar/anchor/util/SepHelper.java b/core/src/main/java/org/stellar/anchor/util/SepHelper.java
index dd3755d9a8..28014bc201 100644
--- a/core/src/main/java/org/stellar/anchor/util/SepHelper.java
+++ b/core/src/main/java/org/stellar/anchor/util/SepHelper.java
@@ -55,6 +55,11 @@ public static void validateAmount(String amount) throws AnchorException {
   }
 
   public static BigDecimal validateAmount(String messagePrefix, String amount)
+      throws AnchorException {
+    return validateAmount(messagePrefix, amount, false);
+  }
+
+  public static BigDecimal validateAmount(String messagePrefix, String amount, boolean allowZero)
       throws BadRequestException {
     // assetName
     if (StringHelper.isEmpty(amount)) {
@@ -67,8 +72,15 @@ public static BigDecimal validateAmount(String messagePrefix, String amount)
     } catch (NumberFormatException e) {
       throw new BadRequestException(messagePrefix + "amount is invalid", e);
     }
-    if (sAmount.signum() < 1) {
-      throw new BadRequestException(messagePrefix + "amount should be positive");
+
+    if (allowZero) {
+      if (sAmount.signum() < 0) {
+        throw new BadRequestException(messagePrefix + "amount should be non-negative");
+      }
+    } else {
+      if (sAmount.signum() < 1) {
+        throw new BadRequestException(messagePrefix + "amount should be positive");
+      }
     }
     return sAmount;
   }
diff --git a/platform/src/main/java/org/stellar/anchor/platform/service/TransactionService.java b/platform/src/main/java/org/stellar/anchor/platform/service/TransactionService.java
index 881a452ded..e3afa9523c 100644
--- a/platform/src/main/java/org/stellar/anchor/platform/service/TransactionService.java
+++ b/platform/src/main/java/org/stellar/anchor/platform/service/TransactionService.java
@@ -162,7 +162,7 @@ void updateSep31Transaction(PatchTransactionRequest ptr, Sep31Transaction txn)
     if (ptr.getAmountFee() != null
         && (!Objects.equals(txn.getAmountFee(), ptr.getAmountFee().getAmount())
             || !Objects.equals(txn.getAmountFeeAsset(), ptr.getAmountFee().getAsset()))) {
-      validateAsset("amount_fee", ptr.getAmountFee());
+      validateAsset("amount_fee", ptr.getAmountFee(), true);
       txn.setAmountFee(ptr.getAmountFee().getAmount());
       txn.setAmountFeeAsset(ptr.getAmountFee().getAsset());
       txWasUpdated = true;
@@ -236,12 +236,17 @@ void validateIfStatusIsSupported(String status) throws BadRequestException {
    * @throws BadRequestException if the provided asset is not supported
    */
   void validateAsset(String fieldName, Amount amount) throws BadRequestException {
+    validateAsset(fieldName, amount, false);
+  }
+
+  void validateAsset(String fieldName, Amount amount, boolean allowZero)
+      throws BadRequestException {
     if (amount == null) {
       return;
     }
 
     // asset amount needs to be non-empty and valid
-    SepHelper.validateAmount(fieldName + ".", amount.getAmount());
+    SepHelper.validateAmount(fieldName + ".", amount.getAmount(), allowZero);
 
     // asset name cannot be empty
     if (StringHelper.isEmpty(amount.getAsset())) {