diff --git a/src/main/java/com/andrewlalis/perfin/model/Account.java b/src/main/java/com/andrewlalis/perfin/model/Account.java
index 6d73a35..f974117 100644
--- a/src/main/java/com/andrewlalis/perfin/model/Account.java
+++ b/src/main/java/com/andrewlalis/perfin/model/Account.java
@@ -8,9 +8,9 @@ import java.util.Currency;
  * credit-card, etc.).
  */
 public class Account {
-    private long id;
-    private LocalDateTime createdAt;
-    private boolean archived;
+    private final long id;
+    private final LocalDateTime createdAt;
+    private final boolean archived;
 
     private AccountType type;
     private String accountNumber;
@@ -27,14 +27,6 @@ public class Account {
         this.currency = currency;
     }
 
-    public Account(AccountType type, String accountNumber, String name, Currency currency) {
-        this.archived = false;
-        this.type = type;
-        this.accountNumber = accountNumber;
-        this.name = name;
-        this.currency = currency;
-    }
-
     public AccountType getType() {
         return type;
     }
diff --git a/src/main/java/com/andrewlalis/perfin/model/AccountEntry.java b/src/main/java/com/andrewlalis/perfin/model/AccountEntry.java
index ee52323..fbf34e0 100644
--- a/src/main/java/com/andrewlalis/perfin/model/AccountEntry.java
+++ b/src/main/java/com/andrewlalis/perfin/model/AccountEntry.java
@@ -36,13 +36,13 @@ public class AccountEntry {
         DEBIT
     }
 
-    private long id;
-    private LocalDateTime timestamp;
-    private long accountId;
-    private long transactionId;
-    private BigDecimal amount;
-    private Type type;
-    private Currency currency;
+    private final long id;
+    private final LocalDateTime timestamp;
+    private final long accountId;
+    private final long transactionId;
+    private final BigDecimal amount;
+    private final Type type;
+    private final Currency currency;
 
     public AccountEntry(long id, LocalDateTime timestamp, long accountId, long transactionId, BigDecimal amount, Type type, Currency currency) {
         this.id = id;
@@ -54,14 +54,6 @@ public class AccountEntry {
         this.currency = currency;
     }
 
-    public AccountEntry(long accountId, long transactionId, BigDecimal amount, Type type, Currency currency) {
-        this.accountId = accountId;
-        this.transactionId = transactionId;
-        this.amount = amount;
-        this.type = type;
-        this.currency = currency;
-    }
-
     public long getId() {
         return id;
     }
diff --git a/src/main/java/com/andrewlalis/perfin/model/AccountType.java b/src/main/java/com/andrewlalis/perfin/model/AccountType.java
index 2de9ba3..79626d9 100644
--- a/src/main/java/com/andrewlalis/perfin/model/AccountType.java
+++ b/src/main/java/com/andrewlalis/perfin/model/AccountType.java
@@ -1,5 +1,8 @@
 package com.andrewlalis.perfin.model;
 
+/**
+ * Represents the different possible account types in Perfin.
+ */
 public enum AccountType {
     CHECKING("Checking"),
     SAVINGS("Savings"),
diff --git a/src/main/java/com/andrewlalis/perfin/model/Attachment.java b/src/main/java/com/andrewlalis/perfin/model/Attachment.java
index 927cb41..282e86e 100644
--- a/src/main/java/com/andrewlalis/perfin/model/Attachment.java
+++ b/src/main/java/com/andrewlalis/perfin/model/Attachment.java
@@ -12,11 +12,11 @@ import java.time.format.DateTimeFormatter;
  * account balance record.
  */
 public class Attachment {
-    private long id;
-    private LocalDateTime timestamp;
-    private String identifier;
-    private String filename;
-    private String contentType;
+    private final long id;
+    private final LocalDateTime timestamp;
+    private final String identifier;
+    private final String filename;
+    private final String contentType;
 
     public Attachment(long id, LocalDateTime timestamp, String identifier, String filename, String contentType) {
         this.id = id;
@@ -26,13 +26,6 @@ public class Attachment {
         this.contentType = contentType;
     }
 
-    public Attachment(LocalDateTime timestamp, String identifier, String filename, String contentType) {
-        this.timestamp = timestamp;
-        this.identifier = identifier;
-        this.filename = filename;
-        this.contentType = contentType;
-    }
-
     public long getId() {
         return id;
     }
diff --git a/src/main/java/com/andrewlalis/perfin/model/BalanceRecord.java b/src/main/java/com/andrewlalis/perfin/model/BalanceRecord.java
index f61db88..f5d795d 100644
--- a/src/main/java/com/andrewlalis/perfin/model/BalanceRecord.java
+++ b/src/main/java/com/andrewlalis/perfin/model/BalanceRecord.java
@@ -10,12 +10,12 @@ import java.util.Currency;
  * correct balance.
  */
 public class BalanceRecord {
-    private long id;
-    private LocalDateTime timestamp;
+    private final long id;
+    private final LocalDateTime timestamp;
 
-    private long accountId;
-    private BigDecimal balance;
-    private Currency currency;
+    private final long accountId;
+    private final BigDecimal balance;
+    private final Currency currency;
 
     public BalanceRecord(long id, LocalDateTime timestamp, long accountId, BigDecimal balance, Currency currency) {
         this.id = id;
@@ -25,12 +25,6 @@ public class BalanceRecord {
         this.currency = currency;
     }
 
-    public BalanceRecord(long accountId, BigDecimal balance, Currency currency) {
-        this.accountId = accountId;
-        this.balance = balance;
-        this.currency = currency;
-    }
-
     public long getId() {
         return id;
     }
diff --git a/src/main/java/com/andrewlalis/perfin/model/Transaction.java b/src/main/java/com/andrewlalis/perfin/model/Transaction.java
index 6527987..d3704c7 100644
--- a/src/main/java/com/andrewlalis/perfin/model/Transaction.java
+++ b/src/main/java/com/andrewlalis/perfin/model/Transaction.java
@@ -16,7 +16,7 @@ public class Transaction {
 
     private final BigDecimal amount;
     private final Currency currency;
-    private String description;
+    private final String description;
 
     public Transaction(long id, LocalDateTime timestamp, BigDecimal amount, Currency currency, String description) {
         this.id = id;
diff --git a/src/main/java/com/andrewlalis/perfin/model/history/AccountHistoryItem.java b/src/main/java/com/andrewlalis/perfin/model/history/AccountHistoryItem.java
index 32a4fbb..4d1e4e1 100644
--- a/src/main/java/com/andrewlalis/perfin/model/history/AccountHistoryItem.java
+++ b/src/main/java/com/andrewlalis/perfin/model/history/AccountHistoryItem.java
@@ -9,10 +9,10 @@ import java.time.LocalDateTime;
  * record, or modifications to the account's properties.
  */
 public class AccountHistoryItem {
-    private long id;
-    private LocalDateTime timestamp;
-    private long accountId;
-    private AccountHistoryItemType type;
+    private final long id;
+    private final LocalDateTime timestamp;
+    private final long accountId;
+    private final AccountHistoryItemType type;
 
     public AccountHistoryItem(long id, LocalDateTime timestamp, long accountId, AccountHistoryItemType type) {
         this.id = id;
@@ -21,12 +21,6 @@ public class AccountHistoryItem {
         this.type = type;
     }
 
-    public AccountHistoryItem(LocalDateTime timestamp, long accountId, AccountHistoryItemType type) {
-        this.timestamp = timestamp;
-        this.accountId = accountId;
-        this.type = type;
-    }
-
     public long getId() {
         return id;
     }