only allow one account per config and allocation
diff --git a/api/src/main/java/io/mifos/payroll/api/v1/domain/PayrollAllocation.java b/api/src/main/java/io/mifos/payroll/api/v1/domain/PayrollAllocation.java
index 3a4d42c..ad606f4 100644
--- a/api/src/main/java/io/mifos/payroll/api/v1/domain/PayrollAllocation.java
+++ b/api/src/main/java/io/mifos/payroll/api/v1/domain/PayrollAllocation.java
@@ -59,4 +59,19 @@
   public void setProportional(final Boolean proportional) {
     this.proportional = proportional;
   }
+
+  @Override
+  public boolean equals(final Object o) {
+    if (this == o) return true;
+    if (o == null || getClass() != o.getClass()) return false;
+
+    final PayrollAllocation that = (PayrollAllocation) o;
+
+    return accountNumber != null ? accountNumber.equals(that.accountNumber) : that.accountNumber == null;
+  }
+
+  @Override
+  public int hashCode() {
+    return accountNumber != null ? accountNumber.hashCode() : 0;
+  }
 }