diff --git a/src/libs/models/BankAccount.js b/src/libs/models/BankAccount.ts
similarity index 51%
rename from src/libs/models/BankAccount.js
rename to src/libs/models/BankAccount.ts
index c4366a48aa6a..6fd77b161aa9 100644
--- a/src/libs/models/BankAccount.js
+++ b/src/libs/models/BankAccount.ts
@@ -1,10 +1,24 @@
 import Str from 'expensify-common/lib/str';
-import lodashGet from 'lodash/get';
-import lodashHas from 'lodash/has';
-import _ from 'underscore';
+import {ValueOf} from 'type-fest';
 import CONST from '@src/CONST';
+import BankAccountJSON, {AdditionalData} from '@src/types/onyx/BankAccount';
+
+type State = ValueOf<typeof BankAccount.STATE>;
+
+type ACHData = {
+    routingNumber: string;
+    accountNumber: string;
+    addressName: string;
+    isSavings: boolean;
+    bankAccountID: number;
+    state: State;
+    validateCodeExpectedDate: string;
+    needsToUpgrade: boolean;
+};
 
 class BankAccount {
+    json: BankAccountJSON;
+
     static STATE = {
         PENDING: 'PENDING',
         OPEN: 'OPEN',
@@ -14,14 +28,12 @@ class BankAccount {
         VERIFYING: 'VERIFYING',
     };
 
-    constructor(accountJSON) {
+    constructor(accountJSON: BankAccountJSON) {
         this.json = accountJSON;
     }
 
     /**
      * Return the ID of the reimbursement account
-     *
-     * @returns {Number}
      */
     getID() {
         return this.json.methodID;
@@ -30,61 +42,43 @@ class BankAccount {
     /**
      * Return the account number, which has been obfuscated by the back end
      * example "XXXXXX3956"
-     *
-     * @returns {String}
      */
     getMaskedAccountNumber() {
-        return this.json.accountData.accountNumber;
+        return this.json.accountData?.accountNumber;
     }
 
     /**
      * Used as the display name for the account...
-     * @returns {String}
      */
     getAddressName() {
-        return this.json.accountData.addressName;
+        return this.json.accountData?.addressName;
     }
 
-    /**
-     * @returns {String}
-     */
     getProcessor() {
-        return this.json.accountData.processor;
+        return this.json.accountData?.processor;
     }
 
-    /**
-     * @returns {String}
-     */
     getRoutingNumber() {
-        return this.json.accountData.routingNumber;
+        return this.json.accountData?.routingNumber;
     }
 
     /**
      * Get all user emails that have access to this bank account
-     * @return {String[]}
      */
     getSharees() {
-        return this.json.accountData.sharees;
+        return this.json.accountData?.sharees;
     }
 
-    /**
-     * @returns {String}
-     * @private
-     */
     getState() {
-        return this.json.accountData.state;
+        return this.json.accountData?.state;
     }
 
-    /**
-     * @returns {Boolean}
-     */
     isOpen() {
         return this.getState() === BankAccount.STATE.OPEN;
     }
 
     /**
      * @deprecated Use !isPending instead.
-     * @returns {Boolean}
      */
     isVerified() {
         return !this.isPending();
@@ -92,7 +86,6 @@ class BankAccount {
 
     /**
      * If the user still needs to enter the 3 micro deposit amounts.
-     * @returns {Boolean}
      */
     isPending() {
         return this.getState() === BankAccount.STATE.PENDING;
@@ -100,7 +93,6 @@ class BankAccount {
 
     /**
      * If success team is currently verifying the bank account data provided by the user.
-     * @returns {Boolean}
      */
     isVerifying() {
         return this.getState() === BankAccount.STATE.VERIFYING;
@@ -108,158 +100,132 @@ class BankAccount {
 
     /**
      * If the user didn't finish entering all their info.
-     * @returns {Boolean}
      */
     isInSetup() {
         return this.getState() === BankAccount.STATE.SETUP;
     }
 
-    /**
-     * @returns {Boolean}
-     */
     isLocked() {
         return this.getState() === BankAccount.STATE.LOCKED;
     }
 
     /**
      * Is it the account to use by default to receive money?
-     *
-     * @returns {Boolean}
      */
     isDefaultCredit() {
-        return this.json.accountData.defaultCredit === true;
+        return this.json.accountData?.defaultCredit === true;
     }
 
     /**
      * Can we use this account to pay other people?
-     *
-     * @returns {Boolean}
      */
     isWithdrawal() {
-        return this.json.accountData.allowDebit === true;
+        return this.json.accountData?.allowDebit === true;
     }
 
     getType() {
-        return this.json.accountData.type;
+        return this.json.accountData?.type;
     }
 
     /**
      * Return the client ID of this bank account
      *
      * @NOTE WARNING KEEP IN SYNC WITH THE PHP
-     * @returns {String}
      */
     getClientID() {
         // eslint-disable-next-line max-len
-        return `${Str.makeID(this.getMaskedAccountNumber())}${Str.makeID(this.getAddressName())}${Str.makeID(this.getRoutingNumber())}${this.getTransactionType()}`;
+        return `${Str.makeID(this.getMaskedAccountNumber() ?? '')}${Str.makeID(this.getAddressName() ?? '')}${Str.makeID(this.getRoutingNumber() ?? '')}${this.getTransactionType()}`;
     }
 
-    /**
-     * @returns {String}
-     * @private
-     */
-    getTransactionType() {
+    private getTransactionType() {
         return this.isWithdrawal() ? 'withdrawal' : 'direct-deposit';
     }
 
     /**
      * Return the internal json data structure used by auth
-     * @returns {Object}
      */
     getJSON() {
         return this.json;
     }
 
     /**
-     * Return whether or not this bank account has been risk checked
-     * @returns {Boolean}
+     * Return whether this bank account has been risk checked
      */
     isRiskChecked() {
-        return Boolean(this.json.accountData.riskChecked);
+        return Boolean(this.json.accountData?.riskChecked);
     }
 
     /**
      * Return when the 3 micro amounts for validation were supposed to reach the bank account.
-     * @returns {String}
      */
     getValidateCodeExpectedDate() {
-        return this.json.validateCodeExpectedDate || '';
+        return this.json.validateCodeExpectedDate ?? '';
     }
 
     /**
      * In which country is the bank account?
-     * @returns {string}
      */
     getCountry() {
-        return lodashGet(this.json, ['accountData', 'additionalData', 'country'], CONST.COUNTRY.US);
+        return this.json.accountData?.additionalData?.country ?? CONST.COUNTRY.US;
     }
 
     /**
      * In which currency is the bank account?
-     * @returns {String}
      */
     getCurrency() {
-        return lodashGet(this.json, ['accountData', 'additionalData', 'currency'], 'USD');
+        return this.json.accountData?.additionalData?.currency ?? 'USD';
     }
 
     /**
      * In which bank is the bank account?
-     * @returns {String}
      */
     getBankName() {
-        return lodashGet(this.json, ['accountData', 'additionalData', 'bankName'], '');
+        return this.json.accountData?.additionalData?.bankName ?? '';
     }
 
     /**
      * Did we get bank account details for local transfer or international wire?
-     * @returns {Boolean}
      */
     hasInternationalWireDetails() {
-        return lodashGet(this.json, ['accountData', 'additionalData', 'fieldsType'], 'local') === 'international';
+        return (this.json.accountData?.additionalData?.fieldsType ?? 'local') === 'international';
     }
 
     /**
      * Get the additional data of a bankAccount
-     * @returns {Object}
      */
-    getAdditionalData() {
-        return this.json.accountData.additionalData || {};
+    getAdditionalData(): Partial<AdditionalData> {
+        return this.json.accountData?.additionalData ?? {};
     }
 
     /**
      * Get the pending action of the bank account
-     * @returns {String}
      */
     getPendingAction() {
-        return lodashGet(this.json, 'pendingAction', '');
+        return this.json.pendingAction ?? '';
     }
 
     /**
-     * Return a map needed to setup a withdrawal account
-     * @returns {Object}
+     * Return a map needed to set up a withdrawal account
      */
-    toACHData() {
-        return _.extend(
-            {
-                routingNumber: this.getRoutingNumber(),
-                accountNumber: this.getMaskedAccountNumber(),
-                addressName: this.getAddressName(),
-                isSavings: this.json.isSavings,
-                bankAccountID: this.getID(),
-                state: this.getState(),
-                validateCodeExpectedDate: this.getValidateCodeExpectedDate(),
-                needsToUpgrade: this.needsToUpgrade(),
-            },
-            this.getAdditionalData(),
-        );
+    toACHData(): Partial<ACHData> {
+        return {
+            routingNumber: this.getRoutingNumber(),
+            accountNumber: this.getMaskedAccountNumber(),
+            addressName: this.getAddressName(),
+            isSavings: this.json.isSavings,
+            bankAccountID: this.getID(),
+            state: this.getState(),
+            validateCodeExpectedDate: this.getValidateCodeExpectedDate(),
+            needsToUpgrade: this.needsToUpgrade(),
+            ...this.getAdditionalData(),
+        } as ACHData;
     }
 
     /**
      * Check if user hasn't upgraded their bank account yet.
-     * @return {Boolean}
      */
     needsToUpgrade() {
-        return !this.isInSetup() && !lodashHas(this.json, ['accountData', 'additionalData', 'beneficialOwners']);
+        return !this.isInSetup() && this.json.accountData?.additionalData?.beneficialOwners === undefined;
     }
 }
 
diff --git a/src/types/onyx/BankAccount.ts b/src/types/onyx/BankAccount.ts
index 2b2bee7df6b0..4dd46c82f800 100644
--- a/src/types/onyx/BankAccount.ts
+++ b/src/types/onyx/BankAccount.ts
@@ -2,6 +2,15 @@ import CONST from '@src/CONST';
 import AccountData from './AccountData';
 import * as OnyxCommon from './OnyxCommon';
 
+type AdditionalData = {
+    isP2PDebitCard?: boolean;
+    beneficialOwners?: string[];
+    currency?: string;
+    bankName?: string;
+    fieldsType?: string;
+    country?: string;
+};
+
 type BankAccount = {
     /** The bank account type */
     accountType?: typeof CONST.PAYMENT_METHODS.PERSONAL_BANK_ACCOUNT;
@@ -11,6 +20,12 @@ type BankAccount = {
 
     isDefault?: boolean;
 
+    /* Determines if the bank account is a savings account */
+    isSavings?: boolean;
+
+    /** Date when the 3 micro amounts for validation were supposed to reach the bank account. */
+    validateCodeExpectedDate?: string;
+
     /** string like 'bankAccount-{<bankAccountID>}' where <bankAccountID> is the bankAccountID */
     key?: string;
 
@@ -31,4 +46,4 @@ type BankAccount = {
 };
 
 export default BankAccount;
-export type {AccountData};
+export type {AccountData, AdditionalData};