diff --git a/SignalServiceKit/src/Contacts/SignalAccount.h b/SignalServiceKit/src/Contacts/SignalAccount.h
index 8e4fc2668e..381ace4fde 100644
--- a/SignalServiceKit/src/Contacts/SignalAccount.h
+++ b/SignalServiceKit/src/Contacts/SignalAccount.h
@@ -8,6 +8,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 @class Contact;
 @class SignalRecipient;
+@class SignalServiceAddress;
 @class YapDatabaseReadTransaction;
 
 // This class represents a single valid Signal account.
@@ -17,11 +18,15 @@ NS_ASSUME_NONNULL_BEGIN
 // * For non-contacts, the contact property will be nil.
 @interface SignalAccount : TSYapDatabaseObject
 
-// An E164 value identifying the signal account.
-//
-// This is the key property of this class and it
-// will always be non-null.
-@property (nonatomic, readonly) NSString *recipientId;
+/// An E164 value identifying the signal account.
+@property (nullable, nonatomic, readonly) NSString *recipientPhoneNumber;
+
+/// A UUID identifying the signal account.
+@property (nullable, nonatomic, readonly) NSString *recipientUUID;
+
+/// An address representing the signal account. This will be
+/// the UUID, if defined, otherwise it will be the E164 number.
+@property (nonatomic, readonly) SignalServiceAddress *recipientAddress;
 
 // This property is optional and will not be set for
 // non-contact account.
@@ -39,7 +44,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)initWithSignalRecipient:(SignalRecipient *)signalRecipient;
 
-- (instancetype)initWithRecipientId:(NSString *)recipientId;
+- (instancetype)initWithSignalServiceAddress:(SignalServiceAddress *)address;
 
 // --- CODE GENERATION MARKER
 
diff --git a/SignalServiceKit/src/Contacts/SignalAccount.m b/SignalServiceKit/src/Contacts/SignalAccount.m
index 952c27c7c8..9c73b4b115 100644
--- a/SignalServiceKit/src/Contacts/SignalAccount.m
+++ b/SignalServiceKit/src/Contacts/SignalAccount.m
@@ -7,13 +7,14 @@
 #import "NSString+SSK.h"
 #import "OWSPrimaryStorage.h"
 #import "SignalRecipient.h"
+#import <SignalServiceKit/SignalServiceKit-Swift.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
+NSUInteger const SignalAccountSchemaVersion = 1;
+
 @interface SignalAccount ()
-
-@property (nonatomic) NSString *recipientId;
-
+@property (nonatomic, readonly) NSUInteger accountSchemaVersion;
 @end
 
 #pragma mark -
@@ -26,16 +27,41 @@ NS_ASSUME_NONNULL_BEGIN
     return [self initWithRecipientId:signalRecipient.recipientId];
 }
 
-- (instancetype)initWithRecipientId:(NSString *)recipientId
+- (instancetype)initWithSignalServiceAddress:(SignalServiceAddress *)serviceAddress
 {
     if (self = [super init]) {
-        OWSAssertDebug(recipientId.length > 0);
+        if (serviceAddress.isUUID) {
+            _recipientUUID = serviceAddress.stringIdentifier;
+        } else {
+            _recipientPhoneNumber = serviceAddress.stringIdentifier;
+        }
 
-        _recipientId = recipientId;
+        _accountSchemaVersion = SignalAccountSchemaVersion;
     }
     return self;
 }
 
+- (nullable instancetype)initWithCoder:(NSCoder *)coder
+{
+    self = [super initWithCoder:coder];
+    if (!self) {
+        return self;
+    }
+
+    // Migrating from an everyone has a phone number world to a
+    // world in which we have UUIDs
+    if (_accountSchemaVersion == 0) {
+        // Rename recipientId to recipientPhoneNumber
+        _recipientPhoneNumber = [coder decodeObjectForKey:@"recipientId"];
+
+        OWSAssert(_recipientPhoneNumber != nil);
+    }
+
+    _accountSchemaVersion = SignalAccountSchemaVersion;
+
+    return self;
+}
+
 // --- CODE GENERATION MARKER
 
 // This snippet is generated by /Scripts/sds_codegen/sds_generate.py. Do not manually edit it, instead run
@@ -67,11 +93,6 @@ NS_ASSUME_NONNULL_BEGIN
 
 // --- CODE GENERATION MARKER
 
-- (nullable NSString *)uniqueId
-{
-    return _recipientId;
-}
-
 - (nullable NSString *)contactFullName
 {
     return self.contact.fullName.filterStringForDisplay;
@@ -82,6 +103,17 @@ NS_ASSUME_NONNULL_BEGIN
     return _multipleAccountLabelText.filterStringForDisplay;
 }
 
+- (SignalServiceAddress *)recipientAddress
+{
+    if (self.recipientUUID != nil) {
+        return [[SignalServiceAddress alloc] initWithUuidString:self.recipientUUID];
+    } else if (self.recipientPhoneNumber != nil) {
+        return [[SignalServiceAddress alloc] initWithPhoneNumber:self.recipientPhoneNumber];
+    } else {
+        OWSFail(@"unexpectedly have no address for SignalAccount, this should never happen.");
+    }
+}
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/SignalServiceKit/src/Contacts/SignalServiceAddress.swift b/SignalServiceKit/src/Contacts/SignalServiceAddress.swift
index 7e28699a3e..6b4cfc0b24 100644
--- a/SignalServiceKit/src/Contacts/SignalServiceAddress.swift
+++ b/SignalServiceKit/src/Contacts/SignalServiceAddress.swift
@@ -14,23 +14,60 @@ public class SignalServiceAddress: NSObject {
     private let backingAddress: BackingStorage
 
     @objc
-    public init(phoneNumber: String) {
-        self.backingAddress = .phoneNumber(phoneNumber)
+    public init?(phoneNumber: String) {
+        guard !phoneNumber.isEmpty else {
+            owsFailDebug("Unexpectedly initialized signal service address with invalid phone number")
+            return nil
+        }
+        backingAddress = .phoneNumber(phoneNumber)
     }
 
     @objc
     public init(uuid: UUID) {
-        self.backingAddress = .uuid(uuid)
+        backingAddress = .uuid(uuid)
+    }
+
+    @objc
+    public init?(uuidString: String) {
+        guard let uuid = UUID(uuidString: uuidString) else {
+            owsFailDebug("Tried to intialize signal service address with invalid UUID")
+            return nil
+        }
+        backingAddress = .uuid(uuid)
+    }
+
+    @objc
+    public var stringIdentifier: String {
+        switch backingAddress {
+        case .phoneNumber(let phoneNumber):
+            return phoneNumber
+        case .uuid(let uuid):
+            return uuid.uuidString
+        }
+    }
+
+    @objc
+    public var isUUID: Bool {
+        guard case .uuid = backingAddress else {
+            return false
+        }
+        return true
+    }
+
+    @objc
+    public var isPhoneNumber: Bool {
+        guard case .phoneNumber = backingAddress else {
+            return false
+        }
+        return true
     }
 
     @objc
     public var transitional_phoneNumber: String! {
-        switch backingAddress {
-        case .phoneNumber(let phoneNumber):
-            return phoneNumber
-        case .uuid:
+        guard case .phoneNumber(let phoneNumber) = backingAddress else {
             owsFailDebug("transitional_phoneNumber was unexpectedly nil")
             return nil
         }
+        return phoneNumber
     }
 }
diff --git a/SignalServiceKit/src/Storage/Database/SSKAccessors+SDS.h b/SignalServiceKit/src/Storage/Database/SSKAccessors+SDS.h
index 332807026e..966cac80f0 100644
--- a/SignalServiceKit/src/Storage/Database/SSKAccessors+SDS.h
+++ b/SignalServiceKit/src/Storage/Database/SSKAccessors+SDS.h
@@ -152,4 +152,12 @@ NS_ASSUME_NONNULL_BEGIN
 
 #pragma mark -
 
+@interface SignalAccount (SDS)
+
+@property (nonatomic, readonly) NSUInteger accountSchemaVersion;
+
+@end
+
+#pragma mark -
+
 NS_ASSUME_NONNULL_END
diff --git a/SignalServiceKit/src/Storage/FullTextSearchFinder.swift b/SignalServiceKit/src/Storage/FullTextSearchFinder.swift
index 2c88de845d..c7a20b4245 100644
--- a/SignalServiceKit/src/Storage/FullTextSearchFinder.swift
+++ b/SignalServiceKit/src/Storage/FullTextSearchFinder.swift
@@ -229,7 +229,7 @@ public class FullTextSearchFinder: NSObject {
             }
             return self.messageIndexer.index(message, transaction: transaction)
         } else if let signalAccount = object as? SignalAccount {
-            return self.recipientIndexer.index(signalAccount.recipientId, transaction: transaction)
+            return self.recipientIndexer.index(signalAccount.recipientAddress.transitional_phoneNumber, transaction: transaction)
         } else {
             return nil
         }