CastorPrep — Terms of Service

Effective date: July 15, 2026

These Terms of Service ("Terms") are a binding agreement between you and CastorPrep ("CastorPrep," "we," "us," or "our"), which operates the CastorPrep website and application (the "Service"). By creating an account, starting a free trial, or otherwise using the Service, you agree to these Terms and to our Privacy Policy. If you do not agree, do not use the Service.

1. Who we are and what the Service is

CastorPrep is an online exam-preparation platform for NCEES Professional Engineer (PE) examinations. The Service provides original practice problems, full-length timed mock exams, a diagnostic, an AI study tutor, and related study tools for the examinations and depths offered on the Service from time to time. The Service is a study aid — see §4.

2. Eligibility

You must be at least 18 years old and able to form a binding contract to use the Service. By using the Service you represent that you meet these requirements and that the information you provide is accurate.

3. Accounts

You are responsible for activity under your account and for keeping your login credentials secure. Accounts are for a single individual — see §7. Tell us promptly (through the message form at castorprep.com/contact) about any unauthorized use. We may refuse, suspend, or terminate accounts as described in §16.

4. Study aid only — no guarantee of results; not professional advice

Important — please read.

• CastorPrep is a practice and study resource. We do not guarantee that you will pass any PE examination or achieve any particular score. Exam outcomes depend on many factors outside our control. We make no pass guarantee.
• The Service is not engineering, professional, legal, or other expert advice, and is not a substitute for the official materials, specifications, and reference handbook published by NCEES. Always confirm exam scope, rules, and requirements with NCEES and your state licensing board.
• Our content is created for exam preparation and may simplify or generalize for instructional purposes. Do not rely on it for real-world engineering design, professional decisions, or anything affecting health or safety.

5. The AI tutor

The Service includes an AI-powered tutor that responds to your questions about practice problems.

• The AI tutor can produce incomplete, inaccurate, or misleading information. Treat its responses as a study aid to be verified, not as authoritative answers. Do not rely on it for professional, engineering, or other consequential decisions.
• To generate responses, the text you send to the tutor and the related problem and solution context are processed by a third-party AI provider (Anthropic). How this works and how we handle that data is described in our Privacy Policy.
• Your use of the tutor must comply with §7 and with the AI provider's applicable usage policies.

6. Free trial

We currently offer a 7-day free trial that does not require a credit card. One trial per person. We may change, limit, or discontinue trial offers at any time. At the end of the trial, you must select a paid plan to keep full access; if you do not, paid features pause. Because no card is collected during the trial, the trial does not convert into a charge on its own.

7. Acceptable use

You agree not to:

• Share your account, login credentials, or access with anyone else. Access is licensed to one individual. We may monitor for and act on signals of account sharing (for example, concurrent sessions or atypical depth-switching).
• Copy, scrape, reproduce, distribute, publicly post, sell, or sublicense any practice problems, solutions, exhibits, or other Service content, in whole or in part.
• Use the Service or its content to build, train, or improve any competing product, dataset, or model, or to create a derivative question bank.
• Reverse engineer, decompile, or attempt to extract source code or the underlying problem bank, or use bots, scrapers, or other automated means to access the Service.
• Misuse the AI tutor (for example, to generate content unrelated to exam preparation, to attempt to extract other users' data, or to circumvent usage limits).
• Interfere with the Service's security, integrity, or performance, or access accounts or data that are not yours.
• Use the Service unlawfully or in violation of these Terms.

8. Subscriptions, billing, auto-renewal, and cancellation

(Paid plans are processed by our payment provider, Stripe.)

• Plans. We offer (a) a monthly plan and (b) one or more prepaid plans — fixed terms paid in a single payment, and, for returning customers, a discounted renewal term. Current plans and prices are shown on our pricing page. Prices exclude applicable taxes, which may be added.
• Auto-renewal — monthly plan. The monthly plan automatically renews each month at the then-current price until you cancel. We disclose the renewal terms at checkout.
• No auto-renewal — prepaid plans. A prepaid plan is a single prepaid term that does not auto-renew. It ends at the end of the term unless you choose to purchase again. Buying another prepaid term while one is active extends your access from your current end date.
• Cancellation. You may cancel at any time from your account. Cancelling the monthly plan stops future renewals; you keep access through the end of the period you have already paid for, with no proration or partial-month refund. A prepaid plan runs to the end of its prepaid term.
• Refunds. Except where required by law, payments are non-refundable once a billing period begins. Our 7-day free trial is provided so you can evaluate the Service before paying. If a genuine billing error occurs on our end (for example, a duplicate charge or a renewal you had cancelled), contact us through castorprep.com/contact and we will correct it.
• Price changes. We may change prices. For the monthly plan, changes apply to renewals after we give you reasonable advance notice; you may cancel before a change takes effect.
• Failed payments. If a renewal payment fails, we may suspend paid access until payment is resolved.

9. Our intellectual property

The Service and all of its content — including the practice problems, worked solutions, exhibits and diagrams, the diagnostic and mock-exam structures, text, software, design, logos, and the "CastorPrep" name and mark — are owned by CastorPrep or its licensors and are protected by intellectual-property laws. Our practice problems and solutions are original works authored by CastorPrep. Subject to these Terms, we grant you a limited, personal, non-exclusive, non-transferable, revocable license to access and use the Service and its content for your own exam preparation only. All rights not expressly granted are reserved. You receive no ownership in any Service content.

10. Not affiliated with NCEES

CastorPrep is an independent service. It is not affiliated with, authorized by, endorsed by, or sponsored by the National Council of Examiners for Engineering and Surveying (NCEES) or any state licensing board. "PE," "PE Mechanical," "PE Electrical," "PE Power," "NCEES," and related exam names are used descriptively to identify the examination for which we help you prepare; any such marks belong to their respective owners. Our practice materials are independently created and are not reproductions of NCEES examination questions or the NCEES Reference Handbook.

11. Your submissions and feedback

If you send us feedback or suggestions, you grant us a worldwide, royalty-free, perpetual license to use them to operate and improve the Service, without obligation to you. Do not send us anything you are not authorized to share. Your interactions with the AI tutor are governed by our Privacy Policy.

12. Third-party services

The Service relies on third-party providers (for example, hosting, database/authentication, payments, and AI). Your use may also be subject to those providers' terms. We are not responsible for third-party services we do not control.

13. Disclaimers

THE SERVICE AND ALL CONTENT ARE PROVIDED "AS IS" AND "AS AVAILABLE," WITHOUT WARRANTIES OF ANY KIND, whether express, implied, or statutory, including any implied warranties of merchantability, fitness for a particular purpose, accuracy, and non-infringement, to the fullest extent permitted by law. Without limiting §4, we do not warrant that the Service will help you pass any exam, that content or AI-tutor responses are accurate or complete, or that the Service will be uninterrupted or error-free.

14. Limitation of liability

To the fullest extent permitted by law, CastorPrep and its officers, employees, and suppliers will not be liable for any indirect, incidental, special, consequential, or punitive damages, or for any loss of profits, data, goodwill, or exam outcomes, arising out of or relating to the Service. Our total liability for any claim relating to the Service will not exceed the greater of the amount you paid us in the 12 months before the claim or US $100. Some jurisdictions do not allow certain limitations, so some of these may not apply to you.

15. Indemnification

You agree to indemnify and hold CastorPrep harmless from claims and expenses (including reasonable legal fees) arising from your misuse of the Service, your violation of these Terms, or your violation of any law or third-party right.

16. Suspension and termination

We may suspend or terminate your access if you breach these Terms (including §7), if required for security or legal reasons, or if we discontinue the Service. You may stop using the Service and cancel at any time (see §8). On termination, your license under §9 ends; sections that by their nature should survive (including §§4, 9, 10, 13, 14, 15, 18) survive.

17. Changes to the Service and these Terms

We may modify the Service and these Terms. If we make material changes to these Terms, we will provide reasonable notice (for example, by posting the updated Terms with a new effective date or by email). Your continued use after changes take effect constitutes acceptance.

18. Governing law and disputes

These Terms are governed by the laws of the State of Delaware, without regard to conflict-of-laws rules. You and CastorPrep agree to the exclusive jurisdiction and venue of the state and federal courts located in Delaware for any dispute arising out of or relating to these Terms or the Service.

19. Copyright

If you believe content on the Service infringes your copyright, contact us through castorprep.com/contact with enough detail to identify the work and the allegedly infringing material, and we will respond appropriately.

20. Miscellaneous

These Terms (with the Privacy Policy and any plan terms presented at checkout) are the entire agreement between you and CastorPrep regarding the Service. If any provision is unenforceable, the rest remain in effect. Our failure to enforce a provision is not a waiver. You may not assign these Terms; we may assign them in connection with a merger, acquisition, or sale of assets. Neither party is liable for delays caused by events beyond its reasonable control.

21. Contact

Questions about these Terms: send us a message at castorprep.com/contact.