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Terms and Conditions

Last updated: March 2026

These terms form a legally binding agreement between you (the person using 123tax) and 123 TAX LTD (Company Number: 11729244), trading as 123tax (“we”, “us”, “our”).

Please read these terms carefully before using 123tax. By creating an account or using any part of our service, you agree to these terms. If you do not agree, please do not use 123tax.

1. Our service

123tax provides software that helps CIS (Construction Industry Scheme) subcontractors manage their tax affairs, including:

  • Capturing and organising CIS payment statements
  • Tracking allowable business expenses
  • Submitting quarterly updates to HMRC under Making Tax Digital for Income Tax (MTD ITSA)
  • Estimating and supporting claims for CIS tax refunds
  • Facilitating Self Assessment submissions

123tax is software, not an accountancy firm. We are not regulated by the ICAEW, ACCA, or any other professional body. We do not provide personalised tax advice. If you have complex tax affairs or are uncertain about your tax position, we recommend consulting a qualified tax professional.

2. Eligibility

To use 123tax you must:

  • Be at least 18 years old
  • Be a sole trader operating under the Construction Industry Scheme (CIS) in the United Kingdom
  • Have a valid Unique Taxpayer Reference (UTR)
  • Be registered for Self Assessment with HMRC

We reserve the right to refuse registration or suspend accounts that do not meet these criteria.

3. Your account

Registration. You create an account by providing your name, email address, phone number, and UTR. You are responsible for ensuring this information is accurate and keeping it up to date.

Security. You are responsible for keeping your login credentials secure. Do not share your password with anyone. If you suspect unauthorised access to your account, contact us immediately at [email protected].

One account per person. You may not create more than one account. Accounts are personal and non-transferable.

HMRC authorisation. To use features that interact with HMRC, you must authorise 123tax via HMRC's OAuth 2.0 flow. This authorisation can be revoked at any time through your HMRC Government Gateway account. Revoking authorisation will prevent 123tax from submitting to or retrieving data from HMRC on your behalf.

4. WhatsApp service

The 123tax WhatsApp service lets you interact with your account by sending messages and photos to our dedicated WhatsApp number.

By using the WhatsApp service you acknowledge that:

  • Messages are transmitted via Meta's WhatsApp Cloud API, and Meta's own terms and privacy policy apply to that transmission
  • You should not send particularly sensitive information (such as bank account numbers or passwords) via WhatsApp — use the secure web portal for anything beyond CIS statements and expense receipts
  • Opt-in to WhatsApp communication is required; you can opt out at any time by messaging STOP to 0121 312 0696
  • We will retain message content as part of your tax records as set out in our Privacy Policy

5. Your responsibilities

Accuracy of information. You are responsible for the accuracy of the information you provide to 123tax, including CIS statement data, expense amounts, and any other financial information. If you provide inaccurate or incomplete information, your submissions to HMRC may be incorrect. Any resulting tax liability, penalties, or interest imposed by HMRC remains your responsibility.

OCR review. Where you use our document scanning (OCR) feature to capture CIS statements via photo, you must review the extracted data before confirming it. By confirming extracted data you accept responsibility for its accuracy. Our OCR service may not always capture information perfectly, particularly from handwritten, damaged, or low-quality images.

Digital records. Under MTD ITSA, you are legally required to keep digital records of your income and expenses. 123tax helps you do this, but you remain the legally responsible party. We recommend keeping your own copies of important documents independently of 123tax.

HMRC deadlines. You are responsible for ensuring your quarterly updates and annual Self Assessment are submitted on time. 123tax will display upcoming deadlines and send reminders, but we cannot be held responsible if you miss a deadline because you did not use the service in time.

6. Subscription and payment

Pricing. The cost of 123tax is set out on our pricing page. Prices are quoted exclusive of VAT unless otherwise stated.

Billing. We bill monthly or annually depending on your chosen plan. Payment is taken in advance. By providing payment details, you authorise us to charge the applicable fee on each billing date.

Free trial. Where a free trial is offered, it will begin immediately on registration and end on the date stated. You will be notified before any trial converts to a paid subscription.

Cancellation. You may cancel your subscription at any time by visiting your Account settings or contacting us. On cancellation, your subscription continues until the end of the paid period. We do not offer refunds for partial subscription periods.

Non-payment. If payment fails and you do not update your payment details within 14 days of notice from us, we reserve the right to suspend or terminate your account. We will give you reasonable notice before taking this action.

Price changes. We will give you at least 30 days' notice of any price increase. If you do not wish to continue at the new price, you may cancel before the change takes effect.

7. Data and records

Your data belongs to you. You retain ownership of all financial data and records you add to 123tax. We process it on your behalf to deliver the service.

Export. You can export your data from your account settings at any time in a standard format (CSV and PDF).

Retention on cancellation. On cancellation, we will retain your data for the retention periods set out in our Privacy Policy (generally 7 years for tax records). You can request earlier deletion of data that we are not legally required to retain.

8. Our responsibilities and limitations

We will: provide the 123tax service with reasonable care and skill; keep your data secure in accordance with our Privacy Policy; give you reasonable notice of any maintenance or downtime; provide support via WhatsApp and email.

We will not be liable for:

  • Any inaccuracy in tax submissions caused by information you provided that was incorrect or incomplete
  • Penalties, interest, or charges imposed by HMRC
  • Any loss arising from your failure to submit information on time
  • Loss or corruption of data caused by events outside our reasonable control (including failures of third-party services such as HMRC's own systems or Meta's WhatsApp platform)
  • Any indirect, consequential, or economic loss

Uptime. We target 99.5% monthly availability for the web portal and API services. Scheduled maintenance will be communicated in advance wherever possible.

Third-party services. 123tax integrates with HMRC's APIs and Meta's WhatsApp Cloud API. The availability and accuracy of those services is outside our control. We are not responsible for interruptions or errors caused by HMRC or Meta's systems.

Limitation of liability. To the fullest extent permitted by law, our total liability to you in any 12-month period is limited to the total subscription fees you have paid to us in that same period. Nothing in these terms limits liability for death or personal injury caused by our negligence, fraud, or any other liability that cannot lawfully be limited.

9. Acceptable use

You must not use 123tax to:

  • Submit false or fraudulent information to HMRC
  • Impersonate any person or misrepresent your identity
  • Attempt to access another user's account or data
  • Probe, scan, or test the security of our systems without prior written permission
  • Introduce malware or other harmful code
  • Use the service in any way that violates applicable law

We may suspend or terminate your account immediately if we reasonably believe you are in breach of these requirements.

10. Intellectual property

All software, design, content, and trademarks associated with 123tax are owned by or licensed to us. We grant you a limited, non-exclusive, non-transferable licence to use 123tax for the purpose of managing your own tax affairs. You may not copy, modify, reverse-engineer, or redistribute any part of the 123tax software.

HMRC does not endorse 123tax. Use of HMRC API services is subject to HMRC's own terms and does not imply approval or endorsement by HMRC.

11. Changes to these terms

We may update these terms from time to time. We will notify you by email at least 14 days before material changes take effect. Continued use of 123tax after the effective date of the changes constitutes your acceptance of the updated terms.

If you do not agree to the changes, you may cancel your account before they take effect and receive a pro-rata refund for any unused subscription period.

12. Termination

By you: You may close your account at any time via your Account settings.

By us: We may suspend or terminate your account if you breach these terms, if we cease to operate the service, or if required to do so by law. We will give you reasonable notice unless suspension is required immediately to protect the security of the service or other users.

On termination for any reason, your right to use 123tax ends immediately.

13. Governing law and disputes

These terms are governed by the laws of England and Wales. Any disputes will be subject to the exclusive jurisdiction of the courts of England and Wales.

If you have a complaint, please contact us first at [email protected]. We aim to resolve complaints within 10 business days. If we cannot resolve a dispute, you may refer it to an appropriate alternative dispute resolution scheme.

14. Contact