Terms of Service

Effective Date: 7 May 2026 · Last Updated: 7 May 2026

These Terms of Service (“Terms”) are a legal agreement between you (“Customer”, “you”, “your”) and Subnet Calc Limited, a company registered in England and Wales (company number 17177789) (“Subnet Calc”, “we”, “us”, “our”).

By creating an account, accessing, or using the Subnet Calc service at www.subnetcalc.com (the “Service”), you agree to be bound by these Terms. If you do not agree, do not use the Service.

1. Definitions

  • “Service” means the Subnet Calc web application, APIs, and all related services provided at www.subnetcalc.com and its regional subdomains.
  • “Account” means your registered user account on the Service.
  • “Team” means an organisation workspace within the Service, comprising one or more members.
  • “Project” means a subnet design created and stored within the Service.
  • “Subscription” means a paid plan providing access to premium features and increased limits.
  • “Content” means all data, subnet designs, project configurations, and other materials you create, upload, or store using the Service.

2. Eligibility

You must be at least 18 years old (or the age of majority in your jurisdiction) to use the Service. By creating an Account, you represent that you meet this requirement. If you are using the Service on behalf of an organisation, you represent that you have authority to bind that organisation to these Terms.

3. Account Registration and Security

3.1. You must authenticate using a supported third-party identity provider (Microsoft, Google, or Apple). We do not store passwords.

3.2. You are responsible for maintaining the security of your third-party authentication credentials and for all activity under your Account.

3.3. You must notify us promptly if you become aware of any unauthorised use of your Account.

3.4. We reserve the right to suspend or terminate Accounts that violate these Terms or are used for unauthorised purposes.

4. Use of the Service

4.1 Permitted Use

You may use the Service to design, manage, and collaborate on IPv4 and IPv6 subnet configurations for legitimate network planning purposes.

4.2 Acceptable Use

You agree not to:

  • (a) use the Service for any unlawful purpose or in violation of any applicable laws or regulations;
  • (b) attempt to gain unauthorised access to the Service, other users' Accounts, or any systems or networks connected to the Service;
  • (c) interfere with or disrupt the integrity or performance of the Service;
  • (d) reverse engineer, decompile, or disassemble any part of the Service;
  • (e) use the Service to transmit malware, viruses, or other harmful code;
  • (f) use automated means (bots, scrapers, crawlers) to access the Service without our prior written consent;
  • (g) resell, sublicense, or redistribute access to the Service without our prior written consent;
  • (h) use the Service in a manner that exceeds reasonable usage or places an unreasonable load on our infrastructure.

4.3 Enforcement

We may suspend or terminate your access if we reasonably believe you have violated the Acceptable Use terms. Where practicable, we will provide notice before suspension, except where immediate action is necessary to protect the Service or other users.

5. Subscriptions and Payment

The provisions of this section 5 are supplemented by our Subscription Terms, which describe each Plan’s limits, the lifetime offer cap, and detailed billing behaviour. In the event of any conflict between this section 5 and the Subscription Terms, this section 5 prevails.

5.1 Free Tier

The Service offers a free tier that does not require a Subscription. Free-tier users may use the subnet designer without creating an Account or saving projects to the cloud. The free tier is subject to the limitations described on our pricing page.

5.2 Paid Plans

Paid Subscriptions (“Plans”) unlock additional features, higher project limits, and team collaboration capabilities. Available Plans and their current pricing are described on our pricing page.

5.3 Billing

  • (a) All paid Plans are billed annually in advance.
  • (b) Payments are processed by Stripe. By subscribing, you also agree to Stripe's Terms of Service.
  • (c) Prices are displayed in your local currency where supported via Stripe Adaptive Pricing. All prices are inclusive of applicable taxes unless stated otherwise.
  • (d) Stripe Tax is used to calculate and collect applicable sales tax, VAT, or GST based on your location.

5.4 Auto-Renewal

Subscriptions renew automatically at the end of each billing period unless cancelled before the renewal date. We will send a renewal receipt via email upon each successful renewal.

5.5 Price Changes

We may change Plan pricing with at least 30 days' written notice (via email to the address associated with your Account). Price changes take effect at the start of your next billing period following the notice period. If you do not agree with a price change, you may cancel your Subscription before the new price takes effect.

5.6 Failed Payments

If a payment fails, Stripe will automatically retry the charge (typically up to four attempts over three to four weeks). If all retry attempts fail, your Subscription will be automatically cancelled. We will notify you by email of payment failures.

5.7 Lifetime Subscriptions

Lifetime Subscriptions are one-time purchases that provide perpetual access to the associated Plan features. Lifetime Subscriptions:

  • (a) are limited in availability (total claims are capped);
  • (b) are non-refundable;
  • (c) cannot be upgraded or downgraded — you must cancel the Lifetime Subscription and purchase a new Subscription if you wish to change Plans;
  • (d) provide access for the lifetime of the Service (subject to section 12, Termination).

6. Cancellation and Refunds

6.1. You may cancel your Subscription at any time through the Service. Cancellation takes effect at the end of your current billing period — you retain full access until then.

6.2. After your Subscription ends, your Team reverts to the free tier. Your Projects and data are retained in read-only mode for twelve (12) months from the cancellation date.

6.3. After the 12-month read-only period, your data becomes eligible for permanent deletion. We will send a warning email before the read-only period expires.

6.4. Refunds for annual Subscriptions are handled in accordance with our Refund & Cancellation Policy.

6.5. Lifetime Subscriptions are non-refundable.

7. Intellectual Property

7.1 Your Content

You retain all ownership rights in the Content you create using the Service. We do not claim any intellectual property rights over your subnet designs, project configurations, or other data.

7.2 Licence to Us

By using the Service, you grant us a limited, non-exclusive, royalty-free licence to store, process, replicate, and display your Content solely for the purpose of providing and improving the Service. This includes replicating your data across our regional infrastructure as described in our Data Residency Statement.

7.3 Our Intellectual Property

The Service, including its design, code, features, documentation, and branding, is owned by Subnet Calc Limited. These Terms do not grant you any rights to our trademarks, logos, or other brand features.

7.4 Feedback

If you provide suggestions, ideas, or feedback about the Service, we may use them without obligation to you.

8. Privacy and Data Protection

Your use of the Service is subject to our Privacy Policy, which describes how we collect, use, and protect your personal data. By using the Service, you acknowledge that you have read and understood our Privacy Policy.

9. Third-Party Services

The Service integrates with third-party services including Stripe (payments), SendGrid (email), Microsoft, Google, and Apple (authentication), and CookieBot (cookie consent). Your use of these services is subject to their respective terms and privacy policies. We are not responsible for the practices of third-party providers.

10. Service Availability

10.1 Availability Target

We aim to maintain high availability of the Service across our deployed regions. Our availability commitments are described in our Service Level Agreement.

10.2 Maintenance

We may perform scheduled maintenance that temporarily affects Service availability. Where practicable, we will provide advance notice of planned maintenance.

10.3 No Warranty of Uninterrupted Service

While we use commercially reasonable efforts to maintain availability, we do not guarantee uninterrupted or error-free access to the Service.

11. Limitation of Liability

11.1 Disclaimer of Warranties

THE SERVICE IS PROVIDED “AS IS” AND “AS AVAILABLE” WITHOUT WARRANTIES OF ANY KIND, WHETHER EXPRESS, IMPLIED, OR STATUTORY, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT.

11.2 Limitation

TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, SUBNET CALC LIMITED SHALL NOT BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES, OR ANY LOSS OF PROFITS, REVENUE, DATA, OR BUSINESS OPPORTUNITIES, ARISING OUT OF OR RELATED TO YOUR USE OF THE SERVICE.

11.3 Cap on Liability

OUR TOTAL AGGREGATE LIABILITY ARISING OUT OF OR RELATED TO THESE TERMS SHALL NOT EXCEED THE GREATER OF: (A) THE TOTAL AMOUNT YOU PAID TO US IN THE TWELVE (12) MONTHS PRECEDING THE EVENT GIVING RISE TO THE LIABILITY, OR (B) ONE HUNDRED US DOLLARS (US$100).

11.4 Exceptions

Nothing in these Terms excludes or limits liability for: (a) death or personal injury caused by negligence; (b) fraud or fraudulent misrepresentation; or (c) any liability that cannot be excluded or limited by applicable law.

12. Termination

12.1 By You

You may close your Account at any time by submitting a request via our support page. If you have an active Subscription, cancellation terms in section 6 apply.

12.2 By Us

We may suspend or terminate your Account if:

  • (a) you breach these Terms;
  • (b) your use of the Service poses a security risk to the Service or other users;
  • (c) we are required to do so by law; or
  • (d) we cease to offer the Service (with at least 90 days' notice).

12.3 Effect of Termination

Upon termination, your right to use the Service ceases. Data retention following termination is governed by section 6 (Cancellation) and our Privacy Policy.

13. Dispute Resolution

13.1 Governing Law

These Terms are governed by and construed in accordance with the laws of England and Wales, without regard to conflict-of-law principles.

13.2 Dispute Resolution

Any dispute arising out of or in connection with these Terms shall first be attempted to be resolved through good-faith negotiation. If the dispute cannot be resolved within thirty (30) days, either party may submit the dispute to the exclusive jurisdiction of the courts of England and Wales.

14. General Provisions

14.1 Entire Agreement

These Terms, together with our Privacy Policy, Cookie Policy, Refund & Cancellation Policy, and any Subscription-specific terms, constitute the entire agreement between you and Subnet Calc Limited regarding the Service.

14.2 Severability

If any provision of these Terms is found to be unenforceable, the remaining provisions shall continue in full force and effect.

14.3 Waiver

Our failure to enforce any right or provision of these Terms shall not be considered a waiver of those rights.

14.4 Assignment

You may not assign or transfer these Terms without our prior written consent. We may assign these Terms without restriction.

14.5 Modifications

We may update these Terms from time to time. We will notify you of material changes by email or through the Service at least 30 days before they take effect. Your continued use of the Service after changes take effect constitutes acceptance of the updated Terms.

15. Support

Technical support and system maintenance for the Service is provided by Inflecto Systems Ltd on behalf of Subnet Calc Limited. Support enquiries should be submitted via our support page.

16. Contact

For questions about these Terms:

Subnet Calc Limited
Unit 34, 53 Mowbray Street, Sheffield, S3 8EN

Or submit an enquiry via our support page.