> ## Documentation Index > Fetch the complete documentation index at: https://docs.mx.com/llms.txt > Use this file to discover all available pages before exploring further. # List account numbers by account per member > This endpoint returns a list of account numbers associated with the specified `account`. Use this endpoint when you identify the account by the `id` you defined: looking up an account by its `id` requires the `member` it belongs to. ## OpenAPI ````yaml /openapi/platform-api/v20260929.yaml get /users/{user_identifier}/members/{member_identifier}/accounts/{account_identifier}/account_numbers openapi: 3.1.0 info: contact: name: Platform API v20260929 url: https://www.mx.com/products/platform-api description: > The MX Platform API is a powerful, fully-featured API designed to make aggregating and enhancing financial data easy and reliable. It can seamlessly connect your app or website to tens of thousands of financial institutions. ## Version Header Versions are set in the `Accept-Version` header of API requests. Version numbers correspond with the date associated with that version. The example below uses the version `v20260929`. ``` -H 'Accept: application/json' -H 'Accept-Version: v20260929' ``` --- title: Platform API 2026 version: '2026' servers: - url: https://int-api.mx.com - url: https://api.mx.com security: - basicAuth: [] tags: - name: authorization description: Authorization endpoints. - name: accounts description: > The Accounts endpoints represent a user's checking, savings, mortgage, 401(k), or other types of accounts held by a financial institution. An account belongs to a `member`, which represents the user's overall relationship with a particular financial institution. A checking account may be just one part of a larger relationship that could also include a car loan and a savings account. Accounts—and the transactions associated with them—are updated every 24 hours, unless the associated `user` is disabled. You can also create manual accounts. Since a manual account has no credentials tied to the member, the account will never aggregate or include data from a data feed. All manual accounts are automatically created under the Manual Institution member. - name: ach return description: > The features documented here are in a beta state, and this documentation is considered draft material subject to frequent change. Using our Platform API, you can securely submit ACH Returns to reduce your ACH return rates and automate your ACH return process. You can query the status and outcomes of your submitted ACH returns to track progress and access resolution details. - name: budgets description: > Use these endpoints to create and manage budgets for your end users. You can create a budget for a specific category or autogenerate a budget for several categories based on existing transactions. Each budget has a `category_guid`, relating to one of the [categories](/api-reference/platform-api/v20260929/reference/categories#default-categories-and-subcategories). - name: categories description: > A `transaction` can have its `category` set to one of MX’s default categories or a custom category for a specific `user`. See [Default Categories and Subcategories](/api-reference/platform-api/v20260929/reference/categories#default-categories-and-subcategories) for a complete list. - name: data exchange description: > Data Exchange provides a secure mechanism for MX clients to share financial data with authorized service providers, external partners, and vendors. Access is controlled through client grants, which define the scope of data an MX client (issuer) makes available to one or more grantees. Each data exchange request requires both standard Platform API authentication and a valid token passed in the `MX-3DX-TOKEN` request header. - name: deprecated description: Deprecated endpoints. - name: goals description: > Use these endpoints to create and manage goals for a `user`. You can also reposition goals to adjust their priority levels. Every goal has a track type and a meta type. The track type (`track_type_name`) is the overall classification of the goal (debt, savings, retirement, or emergency fund) while the meta type (`meta_type_name`) is the specific classification (like college, house, vacation, and so on). - name: insights description: > Use these endpoints to build customizable user experiences in UIs powered by our Financial Insights data. With Financial Insights, your users will receive personalized insights based on their transaction history. Want to learn more about the product? See [Financial Insights](/products/experience/insights). Looking for a guide to use these endpoints? See [Build Your Own Insights UI](/products/experience/insights/integration-guides/insights-api-guide). - name: institutions description: > Institutions represent a financial institution. A single real-world financial institution may have several `institution` objects on the MX platform. For example, the mortgage division of a financial institution might use a separate system than its everyday banking division, which is different from its credit card division. For more info, see [Institutions Overview](/api-reference/platform-api/v20260929/reference/institutions). - name: investment holdings description: > Investment Data Enhancement lets you connect to an end user's financial institution and retrieve cleansed and enhanced investment data. By combining investment data with retail banking information, you get comprehensive insights into customer financial behaviors, risk tolerance, and investment strategies. You can [read a user's holding](/api-reference/platform-api/v20260929/reference/investment-holdings/read-holding), [list all their holdings](/api-reference/platform-api/v20260929/reference/investment-holdings/list-holdings-by-user), or list their holdings by [account](/api-reference/platform-api/v20260929/reference/investment-holdings/list-holdings-by-account) or [member](/api-reference/platform-api/v20260929/reference/investment-holdings/list-holdings-by-member). You can also [deactivate a user](/api-reference/platform-api/v20260929/reference/investment-holdings/deactivate-user-from-investment-holdings) from the Investment Data Enhancement. This is non-billable. - name: members description: > Members represent the connection between an end user and a financial institution. This institution may represent your institution or another one from which MX is aggregating data. For more info, see [Members Overview](/api-reference/platform-api/v20260929/reference/members). - name: merchants description: > Merchants are representations of a transaction’s origin. For example, if you buy a coffee at Starbucks, the transaction merchant will be `Starbucks`. Use the `merchant_guid` and a `merchant_location_guidon` any `transaction` object to access Merchant endpoints for details like the merchant’s name, logo URL, website, street address, and more. - name: microdeposits description: > Microdeposits is an additional verification method that allows you to verify account details and navigate the process of using microdeposits and the automated clearing house (ACH) system. Make two, small ACH deposits into a consumer's account using the provided account and routing number. You can then require that the end user confirm the exact amount of each deposit to verify that they own the account and meet NACHA’s account verification. For more info, including process flows, setting block lists, and more, see [Microdeposits](/products/connectivity/microdeposits). - name: identity_match description: > Verify user identity by comparing personal information with account owner data from connected financial accounts. - name: monthly cash flow profile description: Use these endpoints to read and update a user's monthly cash flow profile. - name: notifications description: > You can only use notifications endpoints if you’re using the MX mobile application. All notifications created through the API will be of notification type `API_NOTIFICATION`, channel `PUSH`, and will not be associated to an entity. No other channels are supported. The read and list endpoints can return any notification associated with the `user`, including notifications created by MX for other channels besides `PUSH`. - name: processor token description: >- Endpoints for processor partners: request authorization codes and tokens, and read account numbers, balances, and account owner information for a user's accounts. - name: rewards description: >- Use these endpoints to aggregate, list, and read a user's rewards, and to read credit card products. - name: spending plan description: > Use the Spending Plan endpoints to create your own version of our [Spending Plan Widget](/products/experience/pfm/legacy-widget-overviews/spending-plan), which helps end users track their spending throughout the month. To understand key terms and how to best use these endpoints, see [Build Your Own Spending Plan UI](/products/experience/pfm/integration-guides/build-your-own-spending-plan-ui). - name: statements description: > With Statements, you can retrieve a user's monthly account statements in PDF format. This data can be used for solutions like personal financial management or risk analysis. - name: taggings description: > Tags and taggings are two resources in the MX Platform API that, when used together, give end users more control over organizing their transactions. A tag is a custom label that can be applied to a transaction. After you create a tag, use it for tagging. This means you should actually apply the tag to a particular transaction. Together, they're a powerful tool for personalization, customization, and money management. For a guide on creating a tag and then applying it to a specific transaction with a tagging, see [Custom Tags and Taggings](/products/experience/pfm/integration-guides/personalization/). - name: tags description: > Tags and taggings are two resources in the MX Platform API that, when used together, give end users more control over organizing their transactions. A tag is a custom label that can be applied to a transaction. After you create a tag, use it for tagging. This means you should actually apply the tag to a particular transaction. Together, they're a powerful tool for personalization, customization, and money management. For a guide on creating a tag and then applying it to a specific transaction with a tagging, see [Custom Tags and Taggings](/products/experience/pfm/integration-guides/personalization/). - name: transaction rules description: > Transaction Rules allow users to automatically recategorize or rename all similar transactions according to their preferences. This only applies to future transactions. When recategorizing or renaming a transaction, the user will be asked whether they want the new data to apply to the selected transaction or to all future transactions. If they choose to apply it to all future transactions, it will create a transaction rule which will automatically apply the changes going forward. - name: transactions description: > Transactions represent any instance in which money moves into or out of an account. This could be a purchase at a business, a payroll deposit, a transfer from one account to another, an ATM withdrawal, and so on. Transactions are created automatically when a member is successfully aggregated. Each `transaction` belongs to only one `account`. For more info, see [Transactions Overview](/api-reference/platform-api/v20260929/reference/transactions). - name: users description: > Users represent an end user using the Platform API through your web or mobile app. Users are created by MX clients and belong to a specific [client](/products/connectivity/overview/data-architecture#resources) on the platform. - name: verifiable credentials description: > MX provides Verifiable Credential endpoints that comply with web5 standards. For more info, see [Verifiable Credentials Overview](/api-reference/platform-api/v20260929/reference/verifiable-credentials). - name: widgets description: > Use the [Request Widget URL](/api-reference/platform-api/v20260929/reference/widgets/request-widget-url) endpoint to generate a URL that loads one of our widgets. Many request body parameters only work for some widgets. For more info, including widget types, see [Widgets Overview](/api-reference/platform-api/v20260929/reference/widgets). paths: /users/{user_identifier}/members/{member_identifier}/accounts/{account_identifier}/account_numbers: get: tags: - accounts summary: List account numbers by account per member description: > This endpoint returns a list of account numbers associated with the specified `account`. Use this endpoint when you identify the account by the `id` you defined: looking up an account by its `id` requires the `member` it belongs to. operationId: listAccountNumbersByAccountPerMember parameters: - $ref: '#/components/parameters/acceptVersionV20260929' - $ref: '#/components/parameters/userIdentifier' - $ref: '#/components/parameters/memberIdentifier' - $ref: '#/components/parameters/accountIdentifier' - $ref: '#/components/parameters/page' - $ref: '#/components/parameters/recordsPerPageMax1000' responses: '200': content: application/json: schema: $ref: '#/components/schemas/AccountNumberListResponse' description: OK components: parameters: acceptVersionV20260929: name: Accept-Version in: header required: true description: MX Platform API version. schema: type: string default: v20260929 example: v20260929 userIdentifier: description: >- Use either the user `id` you defined or the MX-defined user `guid`. See [Assigning Resource IDs](/products/connectivity/overview/held-data#assigning-resource-ids). in: path required: true name: user_identifier schema: type: string memberIdentifier: description: >- Use either the member `id` you defined or the MX-defined member `guid`. See [Assigning Resource IDs](/products/connectivity/overview/held-data#assigning-resource-ids). name: member_identifier in: path required: true schema: type: string accountIdentifier: description: >- Use either the account `id` you defined or the MX-defined account `guid`. See [Assigning Resource IDs](/products/connectivity/overview/held-data#assigning-resource-ids). in: path required: true name: account_identifier schema: type: string page: description: Results are paginated. Specify current page. example: 1 in: query name: page schema: type: integer recordsPerPageMax1000: description: >- This specifies the number of records to be returned on each page. Defaults to `25`. The valid range is from `10` to `1000`. If the value exceeds `1000`, the default value of `25` will be used instead. example: 10 in: query name: records_per_page schema: type: integer schemas: AccountNumberListResponse: properties: account_numbers: items: $ref: '#/components/schemas/AccountNumberV20260929' type: array pagination: $ref: '#/components/schemas/Pagination' type: object required: - account_numbers - pagination additionalProperties: false AccountNumberV20260929: allOf: - $ref: '#/components/schemas/AccountNumberBaseV20260929' - type: object required: - details properties: details: $ref: '#/components/schemas/AccountNumberDetailsV20260929' account: $ref: '#/components/schemas/AccountBaseV20260929' unevaluatedProperties: false member: $ref: '#/components/schemas/MemberBaseV20260929' unevaluatedProperties: false user: $ref: '#/components/schemas/UserBaseV20260929' unevaluatedProperties: false mx_record: $ref: '#/components/schemas/MxRecordBaseV20260929' unevaluatedProperties: false type: object unevaluatedProperties: false Pagination: additionalProperties: false required: - current_page - per_page - total_entries - total_pages properties: current_page: example: 1 type: integer per_page: example: 25 type: integer total_entries: example: 1 type: integer total_pages: example: 1 type: integer type: object AccountNumberBaseV20260929: properties: guid: description: Unique identifier for the account number. Defined by MX. example: ACN-8899832e-e5b4-42cd-aa25-bbf1dc889a8f type: - string - 'null' ach: oneOf: - $ref: '#/components/schemas/AccountNumberAchV20260929' - type: 'null' eft: oneOf: - $ref: '#/components/schemas/AccountNumberEftV20260929' - type: 'null' type: object required: - guid - ach - eft AccountNumberDetailsV20260929: description: Additional details about the account number. type: object properties: loan_guarantor: description: The guarantor of the student loan. example: U.S. DEPARTMENT OF EDUCATION (123456) type: - string - 'null' loan_reference_number: description: The reference number for the student loan. example: '123456789012345' type: - string - 'null' passed_validation: description: Indicates whether the account number has passed validation. example: true type: - boolean - 'null' required: - loan_guarantor - loan_reference_number - passed_validation additionalProperties: false AccountBaseV20260929: properties: account_number_display: description: >- The account number associated with the account. This will typically be a masked or partial account number. example: '3331261' type: - string - 'null' current_balance: description: The current balance of the account. example: 1000 type: - number - 'null' subtype: description: >- The account's subtype, for example, `PLAN_401_K`, `MONEY_MARKET`, or `HOME_EQUITY`. Each subtype belongs to an account `type`. For a full list of account subtypes and types, see [Accounts](/api-reference/platform-api/v20260929/reference/accounts#account-types). example: CHECKING type: - string - 'null' type: description: >- The type of account. Some account types may include subtypes. For a full list of account types and subtypes, see [Account Types](/api-reference/platform-api/v20260929/reference/accounts#account-types). example: CHECKING type: - string - 'null' enum: - ANY - CASH - CHECKING - CHECKING_LINE_OF_CREDIT - CREDIT_CARD - DIGITAL_WALLET - LOAN - LINE_OF_CREDIT - SAVINGS - INVESTMENT - MORTGAGE - INSURANCE - PREPAID - PROPERTY - null guid: description: Unique identifier for the account. Defined by MX. example: ACT-06d7f44b-caae-0f6e-1384-01f52e75dcb1 type: - string - 'null' id: description: The unique partner-defined identifier for the account. example: '1040434698' type: - string - 'null' name: description: The human-readable name for the `account`. example: Test account 2 type: - string - 'null' nickname: description: An alternate name for the `account`. example: Swiss Account type: - string - 'null' self: description: The API URI path for the account. example: >- /users/USR-11141024-90b3-1bce-cac9-c06ced52ab4c/accounts/ACT-06d7f44b-caae-0f6e-1384-01f52e75dcb1 type: string metadata: description: >- Additional information about the account, as a stringified JSON object. example: some metadata type: - string - 'null' type: object description: >- The base fields for an account. Returned as the `account` companion on related resources such as transactions, statements, and rewards, and as the foundation of full account responses. required: - account_number_display - subtype - type - guid - id - name - nickname - self - current_balance - metadata MemberBaseV20260929: properties: guid: description: The unique identifier for the member. Defined by MX. example: MBR-7c6f361b-e582-15b6-60c0-358f12466b4b type: string id: description: The unique partner-defined identifier for the member. example: unique_id type: - string - 'null' metadata: description: Additional information you can store about the member. example: some metadata type: - string - 'null' name: description: The name of the member. example: MX Bank type: - string - 'null' self: description: The API URI path for the member. example: >- /users/USR-11141024-90b3-1bce-cac9-c06ced52ab4c/members/MBR-7c6f361b-e582-15b6-60c0-358f12466b4b type: string description: >- The base fields for a member, which is a user's connection to an institution. Returned as the `member` companion on related resources such as accounts and transactions, and as the foundation of full member responses. required: - guid - id - metadata - name - self UserBaseV20260929: properties: guid: description: The unique identifier for the user. Defined by MX. example: USR-11141024-90b3-1bce-cac9-c06ced52ab4c type: string id: description: The unique partner-defined identifier for the user. example: unique_id type: - string - 'null' metadata: description: Additional information you can store about the user. example: some metadata type: - string - 'null' self: description: The API URI path for the `user`. example: /users/USR-11141024-90b3-1bce-cac9-c06ced52ab4c type: string description: >- The base fields for a user. Returned as the `user` companion on related resources such as members, accounts, and transactions, and as the foundation of full user responses. required: - guid - id - metadata - self MxRecordBaseV20260929: properties: created_at: description: >- The date and time the resource was created in MX Platform, represented in ISO 8601 format with a timestamp. example: '2025-05-10T18:08:00Z' type: - string - 'null' updated_at: description: > The date and time the resource was last updated in MX Platform, represented in ISO 8601 format with a timestamp. For categories, this field will always be `null` when `is_default` is `true`. example: '2026-02-12T22:48:21Z' type: - string - 'null' description: >- Timestamps for when MX created and last updated the record. Returned as the `mx_record` companion on all resources persisted by MX. These describe the MX record, not the underlying resource at the institution. required: - created_at - updated_at AccountNumberAchV20260929: properties: account_number: description: >- The account number associated with the account. This will typically be a masked or partial account number. example: '3331261' type: - string - 'null' routing_number: description: The routing number for the `account`. example: '68899990000000' type: - string - 'null' type: object required: - account_number - routing_number additionalProperties: false AccountNumberEftV20260929: properties: account_number: description: The account number associated with the account. example: '3331261' type: - string - 'null' institution_number: description: The three-digit number identifying a Canadian banking institution. example: '123' type: - string - 'null' transit_number: description: >- The five-digit number identifying the branch of a Canadian financial institution. example: '12345' type: - string - 'null' type: object required: - institution_number - transit_number - account_number additionalProperties: false securitySchemes: basicAuth: scheme: basic type: http description: > To authenticate with the Platform API, include your Base64-encoded `client_id` and `api_key` in the Authorization header of every request: ``` -H 'Authorization: Basic BASE_64_ENCODING_OF{client_id:api_key}' ``` ````