diff --git a/yarn-project/aztec.js/src/wallet/base_wallet.ts b/yarn-project/aztec.js/src/wallet/base_wallet.ts
index d6226a3fd889..afd861dd421b 100644
--- a/yarn-project/aztec.js/src/wallet/base_wallet.ts
+++ b/yarn-project/aztec.js/src/wallet/base_wallet.ts
@@ -88,6 +88,12 @@ export abstract class BaseWallet implements Wallet {
   getRegisteredAccount(address: AztecAddress): Promise<CompleteAddress | undefined> {
     return this.pxe.getRegisteredAccount(address);
   }
+  registerContact(address: AztecAddress): Promise<AztecAddress> {
+    return this.pxe.registerContact(address);
+  }
+  getContacts(): Promise<AztecAddress[]> {
+    return this.pxe.getContacts();
+  }
   registerContract(contract: {
     /** Instance */ instance: ContractInstanceWithAddress;
     /** Associated artifact */ artifact?: ContractArtifact;
diff --git a/yarn-project/circuit-types/src/interfaces/pxe.ts b/yarn-project/circuit-types/src/interfaces/pxe.ts
index 12a5d873c872..beacd758cea9 100644
--- a/yarn-project/circuit-types/src/interfaces/pxe.ts
+++ b/yarn-project/circuit-types/src/interfaces/pxe.ts
@@ -93,6 +93,23 @@ export interface PXE {
    */
   getRegisteredAccount(address: AztecAddress): Promise<CompleteAddress | undefined>;
 
+  /**
+   * Registers a user contact in PXE.
+   *
+   * Once a new contact is registered, the PXE Service will be able to receive notes tagged from this contact.
+   * Will do nothing if the account is already registered.
+   *
+   * @param address - Address of the user to add to the address book
+   * @returns The address address of the account.
+   */
+  registerContact(address: AztecAddress): Promise<AztecAddress>;
+
+  /**
+   * Retrieves the addresses stored as contacts on this PXE Service.
+   * @returns An array of the contacts on this PXE Service.
+   */
+  getContacts(): Promise<AztecAddress[]>;
+
   /**
    * Registers a contract class in the PXE without registering any associated contract instance with it.
    *
@@ -333,7 +350,7 @@ export interface PXE {
   getSyncStats(): Promise<{ [key: string]: NoteProcessorStats }>;
 
   /**
-   * Returns a Contact Instance given its address, which includes the contract class identifier,
+   * Returns a Contract Instance given its address, which includes the contract class identifier,
    * initialization hash, deployment salt, and public keys hash.
    * TODO(@spalladino): Should we return the public keys in plain as well here?
    * @param address - Deployment address of the contract.
@@ -341,7 +358,7 @@ export interface PXE {
   getContractInstance(address: AztecAddress): Promise<ContractInstanceWithAddress | undefined>;
 
   /**
-   * Returns a Contact Class given its identifier.
+   * Returns a Contract Class given its identifier.
    * TODO(@spalladino): The PXE actually holds artifacts and not classes, what should we return? Also,
    * should the pxe query the node for contract public info, and merge it with its own definitions?
    * @param id - Identifier of the class.
diff --git a/yarn-project/pxe/src/database/kv_pxe_database.ts b/yarn-project/pxe/src/database/kv_pxe_database.ts
index 95a5da82e45b..76309c984dc0 100644
--- a/yarn-project/pxe/src/database/kv_pxe_database.ts
+++ b/yarn-project/pxe/src/database/kv_pxe_database.ts
@@ -36,8 +36,9 @@ import { type PxeDatabase } from './pxe_database.js';
  */
 export class KVPxeDatabase implements PxeDatabase {
   #synchronizedBlock: AztecSingleton<Buffer>;
-  #addresses: AztecArray<Buffer>;
-  #addressIndex: AztecMap<string, number>;
+  #completeAddresses: AztecArray<Buffer>;
+  #completeAddressIndex: AztecMap<string, number>;
+  #addressBook: AztecSet<string>;
   #authWitnesses: AztecMap<string, Buffer[]>;
   #capsules: AztecArray<Buffer[]>;
   #notes: AztecMap<string, Buffer>;
@@ -72,8 +73,10 @@ export class KVPxeDatabase implements PxeDatabase {
   constructor(private db: AztecKVStore) {
     this.#db = db;
 
-    this.#addresses = db.openArray('addresses');
-    this.#addressIndex = db.openMap('address_index');
+    this.#completeAddresses = db.openArray('addresses');
+    this.#completeAddressIndex = db.openMap('address_index');
+
+    this.#addressBook = db.openSet('address_book');
 
     this.#authWitnesses = db.openMap('auth_witnesses');
     this.#capsules = db.openArray('capsules');
@@ -509,15 +512,15 @@ export class KVPxeDatabase implements PxeDatabase {
     return this.#db.transaction(() => {
       const addressString = completeAddress.address.toString();
       const buffer = completeAddress.toBuffer();
-      const existing = this.#addressIndex.get(addressString);
+      const existing = this.#completeAddressIndex.get(addressString);
       if (typeof existing === 'undefined') {
-        const index = this.#addresses.length;
-        void this.#addresses.push(buffer);
-        void this.#addressIndex.set(addressString, index);
+        const index = this.#completeAddresses.length;
+        void this.#completeAddresses.push(buffer);
+        void this.#completeAddressIndex.set(addressString, index);
 
         return true;
       } else {
-        const existingBuffer = this.#addresses.at(existing);
+        const existingBuffer = this.#completeAddresses.at(existing);
 
         if (existingBuffer?.equals(buffer)) {
           return false;
@@ -531,12 +534,12 @@ export class KVPxeDatabase implements PxeDatabase {
   }
 
   #getCompleteAddress(address: AztecAddress): CompleteAddress | undefined {
-    const index = this.#addressIndex.get(address.toString());
+    const index = this.#completeAddressIndex.get(address.toString());
     if (typeof index === 'undefined') {
       return undefined;
     }
 
-    const value = this.#addresses.at(index);
+    const value = this.#completeAddresses.at(index);
     return value ? CompleteAddress.fromBuffer(value) : undefined;
   }
 
@@ -545,7 +548,21 @@ export class KVPxeDatabase implements PxeDatabase {
   }
 
   getCompleteAddresses(): Promise<CompleteAddress[]> {
-    return Promise.resolve(Array.from(this.#addresses).map(v => CompleteAddress.fromBuffer(v)));
+    return Promise.resolve(Array.from(this.#completeAddresses).map(v => CompleteAddress.fromBuffer(v)));
+  }
+
+  async addContactAddress(address: AztecAddress): Promise<boolean> {
+    if (this.#addressBook.has(address.toString())) {
+      return false;
+    }
+
+    await this.#addressBook.add(address.toString());
+
+    return true;
+  }
+
+  getContactAddresses(): AztecAddress[] {
+    return [...this.#addressBook.entries()].map(AztecAddress.fromString);
   }
 
   getSynchedBlockNumberForAccount(account: AztecAddress): number | undefined {
@@ -570,7 +587,7 @@ export class KVPxeDatabase implements PxeDatabase {
       (sum, value) => sum + value.length * Fr.SIZE_IN_BYTES,
       0,
     );
-    const addressesSize = this.#addresses.length * CompleteAddress.SIZE_IN_BYTES;
+    const addressesSize = this.#completeAddresses.length * CompleteAddress.SIZE_IN_BYTES;
     const treeRootsSize = Object.keys(MerkleTreeId).length * Fr.SIZE_IN_BYTES;
 
     return incomingNotesSize + outgoingNotesSize + treeRootsSize + authWitsSize + addressesSize;
diff --git a/yarn-project/pxe/src/database/pxe_database.ts b/yarn-project/pxe/src/database/pxe_database.ts
index db845d06828b..22b0a3a46d97 100644
--- a/yarn-project/pxe/src/database/pxe_database.ts
+++ b/yarn-project/pxe/src/database/pxe_database.ts
@@ -145,6 +145,10 @@ export interface PxeDatabase extends ContractArtifactDatabase, ContractInstanceD
    */
   setHeader(header: Header): Promise<void>;
 
+  addContactAddress(address: AztecAddress): Promise<boolean>;
+
+  getContactAddresses(): AztecAddress[];
+
   /**
    * Adds complete address to the database.
    * @param address - The complete address to add.
diff --git a/yarn-project/pxe/src/pxe_service/pxe_service.ts b/yarn-project/pxe/src/pxe_service/pxe_service.ts
index a06217d61044..d4342fcaf8a0 100644
--- a/yarn-project/pxe/src/pxe_service/pxe_service.ts
+++ b/yarn-project/pxe/src/pxe_service/pxe_service.ts
@@ -204,6 +204,30 @@ export class PXEService implements PXE {
     return accountCompleteAddress;
   }
 
+  public async registerContact(address: AztecAddress): Promise<AztecAddress> {
+    const accounts = await this.keyStore.getAccounts();
+    if (accounts.includes(address)) {
+      this.log.info(`Account:\n "${address.toString()}"\n already registered.`);
+      return address;
+    }
+
+    const wasAdded = await this.db.addContactAddress(address);
+
+    if (wasAdded) {
+      this.log.info(`Added contact:\n ${address.toString()}`);
+    } else {
+      this.log.info(`Contact:\n "${address.toString()}"\n already registered.`);
+    }
+
+    return address;
+  }
+
+  public getContacts(): Promise<AztecAddress[]> {
+    const contacts = this.db.getContactAddresses();
+
+    return Promise.resolve(contacts);
+  }
+
   public async getRegisteredAccounts(): Promise<CompleteAddress[]> {
     // Get complete addresses of both the recipients and the accounts
     const completeAddresses = await this.db.getCompleteAddresses();
diff --git a/yarn-project/pxe/src/simulator_oracle/index.ts b/yarn-project/pxe/src/simulator_oracle/index.ts
index 4295bc1e555a..100233bd640c 100644
--- a/yarn-project/pxe/src/simulator_oracle/index.ts
+++ b/yarn-project/pxe/src/simulator_oracle/index.ts
@@ -230,6 +230,16 @@ export class SimulatorOracle implements DBOracle {
     return this.contractDataOracle.getDebugFunctionName(contractAddress, selector);
   }
 
+  /**
+   * Returns the full contents of your address book.
+   * This is used when calculating tags for incoming notes by deriving the shared secret, the contract-siloed tagging secret, and
+   * finally the index specified tag. We will then query the node with this tag for each address in the address book.
+   * @returns The full list of the users contact addresses.
+   */
+  public getContacts(): AztecAddress[] {
+    return this.db.getContactAddresses();
+  }
+
   /**
    * Returns the tagging secret for a given sender and recipient pair. For this to work, the ivpsk_m of the sender must be known.
    * Includes the last known index used for tagging with this secret.