Last updated: September 27, 2026
These Terms of Service, together with any order, plan, or documentation referenced herein (collectively, the "Terms"), form a binding agreement between you and, if you are entering into these Terms on behalf of a company or other legal entity, that entity ("Customer", "you", or "your"), and BLVCK LLC, a Maryland limited liability company doing business as Stack ("Stack", "we", "us", or "our"). These Terms govern your access to and use of our websites, application programming interfaces, dashboards, data, database exports, and related services (collectively, the "Service").
Please read these Terms carefully. By clicking to accept, creating an account, generating or using an API key, or otherwise accessing or using the Service, you acknowledge that you have read, understood, and agree to be bound by these Terms. If you do not agree, you must not access or use the Service. Section 26 contains a binding arbitration provision and a class-action waiver that affect your legal rights. Please review it carefully.
You must be at least 18 years old and capable of forming a binding contract to use the Service. If you use the Service on behalf of an entity, you represent and warrant that you are authorized to bind that entity to these Terms. You may not use the Service if you are barred from doing so under the laws of the United States or any other applicable jurisdiction, or if you are located in, under the control of, or a national or resident of any country or region subject to comprehensive U.S. sanctions.
To access most features you must create an account and provide accurate, current, and complete information, and keep it up to date. You are responsible for all activity that occurs under your account. You must maintain the confidentiality of your account credentials and notify us immediately at [email protected] of any unauthorized use or suspected breach. We are not liable for any loss or damage arising from your failure to safeguard your account.
Stack issues API Keys to authenticate requests. You are solely responsible for all use of the Service made with your API Keys, whether or not authorized by you, and for keeping your API Keys secret. You agree not to share, publish, or embed API Keys in publicly accessible locations. You are responsible for rotating or pausing your API Keys if you believe they have been compromised. All requests authenticated with your API Keys are deemed to be made by you, and you are responsible for all associated fees and consequences.
Stack provides a routing number validation API and related financial data, and offers Database Exports under separate license terms. The Service is provided on a software-as-a-service basis. We may modify, enhance, add to, or discontinue features of the Service at any time. We will use commercially reasonable efforts to provide continuous availability of the Service but do not guarantee that the Service will be uninterrupted, timely, secure, or error-free.
Access to the API requires an active paid subscription. By subscribing, you authorize us and our third-party payment processor to charge the applicable fees to your designated payment method.
Payments are processed by our third-party payment processor (currently Stripe), and your payment is also subject to the processor's terms and privacy policy. We do not store full payment card numbers on our servers.
Subject to your compliance with these Terms and payment of applicable fees, Stack grants you a limited, non-exclusive, non-transferable, non-sublicensable, revocable license during the term to access and use the API and Stack Data solely for your internal business purposes and only as permitted by these Terms and the Documentation. Database Exports are licensed separately and are subject to the additional license terms provided with each export.
You will not, and will not permit any third party to:
Stack Data is licensed, not sold. As between the parties, Stack and its licensors retain all right, title, and interest in and to Stack Data and the Service. All rights not expressly granted are reserved.
You agree not to use the Service to:
We may investigate suspected violations and may report activity we reasonably believe to be unlawful to appropriate authorities.
The Service may be subject to rate limits and fair-use thresholds. We may throttle, limit, or suspend access that we reasonably determine to be excessive, abusive, automated beyond permitted use, or detrimental to the Service or other users. "Unlimited" plans are subject to fair use and are not a license to resell access or to place undue load on the Service.
Stack Data is compiled from various sources and is provided for informational purposes only. While we strive to maintain accurate and current data, we do not warrant that Stack Data is accurate, complete, current, or fit for any particular purpose. Routing numbers, institution details, ACH eligibility, and related information can change without notice.
You are solely responsible for independently verifying Stack Data before relying on it, and for any decision you make or action you take based on the Service. Stack Data is not, and must not be used as, the sole basis for initiating a payment, transfer, or other financial transaction. The Service does not constitute financial, legal, accounting, compliance, or other professional advice.
You are solely responsible for your products and services and for your compliance with all laws and rules applicable to your use of the Service, including, as applicable, the rules of Nacha and the automated clearing house network, payment network rules, anti-money-laundering and know-your-customer requirements, sanctions administered by the U.S. Office of Foreign Assets Control, consumer-protection laws, and data-protection laws. Stack does not assume, and expressly disclaims, any responsibility for your regulatory or contractual compliance obligations.
You retain all rights in Customer Data. You grant Stack a worldwide, non-exclusive license to host, process, transmit, and use Customer Data as necessary to provide, secure, and improve the Service and to comply with law. You represent and warrant that you have all rights necessary to submit Customer Data and that it does not violate these Terms or any third-party right. We may generate and use aggregated or de-identified data derived from use of the Service, provided it does not identify you.
The Service, Stack Data, software, Documentation, and all related intellectual property are and remain the exclusive property of Stack and its licensors. "Stack" and related names, logos, and marks are trademarks of Stack. These Terms do not grant you any right to use our trademarks or branding without our prior written consent.
If you provide suggestions, ideas, or feedback about the Service, you grant Stack a perpetual, irrevocable, worldwide, royalty-free license to use and incorporate that feedback for any purpose without obligation or compensation to you.
The Service may integrate with or rely on third-party products and services (for example, payment processing and hosting). We are not responsible for third-party services, and your use of them may be subject to their own terms and policies. We do not endorse and are not liable for any third-party services.
"Confidential Information" means non-public information disclosed by one party that is designated as confidential or that reasonably should be understood to be confidential, including the Service, Documentation, non-public features, and pricing. The receiving party will use Confidential Information only to perform under these Terms, protect it with reasonable care, and not disclose it except to personnel and advisors who need to know and are bound by confidentiality obligations. This section does not apply to information that is or becomes public through no fault of the receiving party, is independently developed, or is rightfully obtained from a third party.
We may suspend or restrict your access to the Service, in whole or in part, without liability, if we reasonably believe that: (a) you have violated these Terms; (b) your use poses a security risk or may harm the Service or others; (c) your payment is overdue; or (d) suspension is required by law or requested by a governmental authority. We will use reasonable efforts to notify you where practicable.
These Terms remain in effect while you use the Service. You may terminate by canceling your subscription and ceasing use of the Service. We may terminate or suspend these Terms or your access at any time, with or without cause, and may discontinue the Service. Upon termination: (a) your licenses and right to access the Service end immediately; (b) you must cease using the Service and Stack Data, except that Database Export licenses survive according to their own terms; and (c) accrued payment obligations survive. Sections that by their nature should survive termination will survive, including Sections 7, 10–14, 16, and 19–31.
THE SERVICE AND STACK DATA ARE PROVIDED "AS IS" AND "AS AVAILABLE" WITHOUT WARRANTIES OF ANY KIND, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE. TO THE MAXIMUM EXTENT PERMITTED BY LAW, STACK DISCLAIMS ALL WARRANTIES, INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND NON-INFRINGEMENT, AND ANY WARRANTIES ARISING FROM COURSE OF DEALING OR USAGE OF TRADE. STACK DOES NOT WARRANT THAT THE SERVICE WILL BE UNINTERRUPTED, ERROR-FREE, OR SECURE, OR THAT STACK DATA WILL BE ACCURATE, COMPLETE, OR CURRENT. SOME JURISDICTIONS DO NOT ALLOW THE EXCLUSION OF CERTAIN WARRANTIES, SO SOME OF THE ABOVE MAY NOT APPLY TO YOU.
TO THE MAXIMUM EXTENT PERMITTED BY LAW, IN NO EVENT WILL STACK OR ITS AFFILIATES, LICENSORS, OR SUPPLIERS BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, EXEMPLARY, OR PUNITIVE DAMAGES, OR FOR ANY LOSS OF PROFITS, REVENUE, DATA, GOODWILL, OR BUSINESS, ARISING OUT OF OR RELATED TO THESE TERMS OR THE SERVICE, WHETHER IN CONTRACT, TORT, OR OTHERWISE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
STACK'S TOTAL CUMULATIVE LIABILITY ARISING OUT OF OR RELATED TO THESE TERMS OR THE SERVICE WILL NOT EXCEED THE GREATER OF (A) THE AMOUNTS YOU PAID TO STACK FOR THE SERVICE IN THE TWELVE (12) MONTHS PRECEDING THE EVENT GIVING RISE TO THE CLAIM, OR (B) ONE HUNDRED U.S. DOLLARS ($100). THE FOREGOING LIMITATIONS APPLY EVEN IF A REMEDY FAILS OF ITS ESSENTIAL PURPOSE. SOME JURISDICTIONS DO NOT ALLOW CERTAIN LIMITATIONS, SO SOME OF THE ABOVE MAY NOT APPLY TO YOU.
You will defend, indemnify, and hold harmless Stack and its affiliates, officers, directors, employees, and agents from and against any claims, damages, liabilities, losses, costs, and expenses (including reasonable attorneys' fees) arising out of or related to: (a) your use of the Service; (b) Customer Data; (c) your products, services, or business; (d) your violation of these Terms or applicable law; or (e) your violation of any third-party right. We will provide you with reasonable notice of any such claim and reasonable cooperation, at your expense.
We may modify these Terms at any time. If we make material changes, we will update the "Last updated" date above and, where appropriate, provide additional notice. Changes are effective when posted unless otherwise stated. Your continued use of the Service after changes take effect constitutes acceptance. If you do not agree to the changes, you must stop using the Service.
These Terms and any dispute arising out of or relating to them or the Service are governed by the laws of the State of Maryland and applicable U.S. federal law, without regard to conflict-of-laws principles. Subject to Section 26, the state and federal courts located in Maryland will have exclusive jurisdiction, and you consent to personal jurisdiction and venue there. The United Nations Convention on Contracts for the International Sale of Goods does not apply.
Please read this section carefully. It affects your legal rights.
Before filing a claim, you agree to try to resolve the dispute informally by contacting us at [email protected]. If we cannot resolve the dispute within sixty (60) days, either party may pursue the claim as set out below.
Except for the excluded claims below, any dispute arising out of or relating to these Terms or the Service will be resolved by final and binding individual arbitration administered by a recognized arbitration provider under its applicable rules. The arbitration will be conducted in Maryland (or by videoconference), and judgment on the award may be entered in any court of competent jurisdiction. The Federal Arbitration Act governs the interpretation and enforcement of this section.
You and Stack agree that each may bring claims against the other only in an individual capacity, and not as a plaintiff or class member in any purported class, collective, consolidated, or representative proceeding. You and Stack waive any right to a jury trial.
Either party may bring an individual claim in small-claims court or seek injunctive or equitable relief in court to protect its intellectual property or Confidential Information. You may opt out of this arbitration provision by sending written notice to [email protected] within thirty (30) days of first accepting these Terms; if you opt out, Section 23 governs any dispute.
You represent that you are not located in, and will not use the Service in or for the benefit of, any country or party subject to U.S. sanctions or export restrictions, and that you are not identified on any U.S. government restricted-party list. You will comply with all applicable export control and sanctions laws.
Stack will not be liable for any delay or failure to perform resulting from causes beyond its reasonable control, including acts of God, natural disasters, labor disputes, internet or utility failures, third-party service failures, governmental action, war, terrorism, or cyberattacks.
You may not assign or transfer these Terms without our prior written consent. We may assign these Terms without restriction, including in connection with a merger, acquisition, reorganization, or sale of assets. Any prohibited assignment is void.
We may provide notices to you by email to the address associated with your account, by posting within the Service, or by posting on our website. You may provide notices to us at [email protected]. Notices are deemed given when sent or posted.
BLVCK LLC d/b/a Stack — Maryland, USA. Questions about these Terms can be sent to [email protected].