Terms of Sale
Last updated: 30 October 2026
> Courtesy translation. Only the French version is legally binding: Conditions Générales de Vente. In the event of any discrepancy, the French text prevails.
These Terms of Sale govern sales of subscriptions to the Derja service (derja.fr), and of the “Derja for teams” offer to organisations, offered by Ismael Dubuc, sole trader (SIREN 939 197 554), 30 Allée Sidney Bechet, 93430 Villetaneuse, France, hereinafter “the Seller”.
The Seller is exempt from VAT under article 293 B of the French General Tax Code (small-business exemption). VAT not applicable.
1. Scope
These Terms apply to any subscription order placed on derja.fr, and in the Derja mobile apps for iOS and Android, by a consumer within the meaning of the preliminary article of the French Consumer Code (hereinafter “the Customer”). They apply to the exclusion of any other terms.
Two purchase channels exist side by side, and the arrangements differ by channel:
- Purchase on the web (derja.fr): payment is processed by Stripe and the Seller deals with the Customer directly.
- Purchase from the iOS or Android app: the transaction is carried out by Apple (App Store) or Google (Google Play), which collects the payment and handles billing, renewal, cancellation and refunds. That platform's terms then apply in addition to these, and prevail over them in the event of any conflict on anything concerning payment, renewal and refunds.
The articles below set out, where necessary, the arrangements applicable to each channel.
Business customers. The “Derja for teams” offer, sold on invoice to an organisation acting for its business purposes, is governed by article 18, and by articles 11 (force majeure), 16 (contact) and 17 (payment provider). Articles 2 to 10 and 12 to 15 do not apply to it: they concern the consumer, and in particular the right of withdrawal (articles 6 and 7), the legal guarantee of conformity under the French Consumer Code (article 12) and consumer mediation (article 13) are reserved for consumers.
2. Offers and prices
The offers available at the time of ordering are shown on the site's pricing page. By way of indication, up to and including 30 November 2026:
| Offer | Price | Arrangement |
|---|---|---|
| Monthly | €4.99 / month | Subscription renewing each month |
| Yearly | €34.99 / year | Subscription renewing each year |
| Lifetime | €69.00 | One-off payment, unlimited lifetime access |
From 1 December 2026, for any new subscription:
| Offer | Price | Arrangement |
|---|---|---|
| Monthly | €7.99 / month | Subscription renewing each month |
| Yearly | €49.99 / year | Subscription renewing each year |
| Lifetime | €99.00 | One-off payment, unlimited lifetime access |
Subscriptions taken out before 1 December 2026 keep their price when they renew.
VAT not applicable, art. 293 B of the French General Tax Code.
Prices are stated in euros and are the final prices paid by the Customer: as the Seller is under the VAT small-business exemption, no VAT is added. The Seller reserves the right to change prices at any time. Subscriptions already running are honoured until they end.
Time-limited promotional offers may be made available; the price shown on the payment page at the time of ordering is the one that applies.
3. Ordering process
- The Customer selects the offer they want on the pricing page.
- They are redirected to the secure Stripe payment page.
- They enter their payment details directly in the Stripe interface (banking data does not pass through the Seller's servers).
- They tick the mandatory boxes (acceptance of these Terms, waiver of the right of withdrawal).
- They confirm the order by clicking the confirmation button.
- A confirmation email is sent to the address given at sign-up.
The order is final upon receipt of payment confirmation from Stripe.
4. Payment
Purchase on the web. Payment is made online, securely, via the Stripe, Inc. platform. The accepted payment methods are those offered by Stripe (Visa, Mastercard, etc.).
If payment fails, premium access is not activated. If a recurring subscription goes unpaid, Stripe makes several collection attempts. If payment still fails, premium access is suspended.
Purchase from the mobile app. Payment is charged to the Customer's Apple or Google account when the purchase is confirmed, using the payment methods registered on that account. The Seller has access to no banking data. The prices shown in the app are those set by the platform's price tiers and may differ from the prices on the website.
5. Provision of the service
Access to premium features is activated immediately after Stripe confirms payment, provided the Customer has an active Derja account.
The service is supplied electronically, with no physical medium. The digital content is accessible from any compatible web browser.
6. Right of withdrawal: digital content
In accordance with article L221-28 13° of the French Consumer Code, the right of withdrawal does not apply to digital content not supplied on a physical medium where performance has begun with the consumer's prior express agreement and express waiver of their right of withdrawal.
By confirming their order, the Customer expressly acknowledges:
> *“I expressly request that performance of the contract begin immediately. I therefore acknowledge that I lose my 14-day right of withdrawal once performance of the digital content has begun.”*
This waiver is collected via a mandatory tick box at the time of ordering.
Exception, “Lifetime” offer (one-off payment): For this offer only, if the access has not yet been used (no review session started), the Customer has a 14-day right of withdrawal from the date of the order, in accordance with article L221-18 of the French Consumer Code. To exercise it, contact contact@derja.fr using the form below or any statement unambiguously expressing the wish to withdraw.
7. Withdrawal form (annex)
> For the attention of Ismael Dubuc, contact@derja.fr
>
> I hereby give notice of my withdrawal from the contract for the Derja subscription ordered on [ORDER DATE].
>
> Customer name: ____________________________
> Account email address: ____________________________
> Order date: ____________________________
>
> Signature (if on paper): ____________________________
> Date: ____________________________
8. Automatic renewal of recurring subscriptions
In accordance with article L215-1 of the French Consumer Code, the Seller will inform the Customer by email, no earlier than 3 months and no later than 1 month before the annual renewal date, of the option not to renew the subscription.
Monthly subscriptions renew each month with no specific notice: the Customer may cancel at any time from their Stripe management area.
9. Cancellation
9.1 Recurring subscriptions (Monthly / Yearly): purchased on the web
The Customer may cancel their subscription at any time from the “My account > Manage my subscription” section (Stripe portal). Cancellation takes effect at the end of the current period already paid for. No pro-rata refund is granted for the remaining period, save as provided in article 11.
9.1 bis Recurring subscriptions: purchased from the mobile app
Cancellation is carried out exclusively from the platform account settings, as the Seller has no control over these subscriptions:
- iOS: Settings > [your name] > Subscriptions > Derja+ > Cancel subscription.
- Android: Google Play > Menu > Payments and subscriptions > Subscriptions > Derja+ > Cancel.
The subscription renews automatically unless cancelled at least 24 hours before the end of the current period. Cancellation takes effect at the end of the period already paid for, access being retained until then.
9.2 “Lifetime” offer
The lifetime offer cannot be cancelled (permanent access). It may be subject to withdrawal under the conditions of article 6.
9.3 Account deletion
Deletion of the Customer's account (from “My account” or on written request) immediately cancels the subscription taken out on the website, with no refund for the current period. It ends access to Derja+, including for the lifetime offer.
A subscription taken out on the App Store or Google Play is not cancelled by deleting the account: the Customer must cancel it themselves in the platform settings, as set out in article 9.1 bis, failing which the platform continues to charge for it.
10. Refunds
Apart from the right of withdrawal where applicable, no refund is granted for a subscription in progress. The Seller may nonetheless, as a commercial gesture and at its discretion, grant a partial refund in the event of a technical problem attributable to the service that made it unusable for a significant period.
Purchases made from the mobile app. Refunds are exclusively a matter for Apple or Google, which collected the payment. The Seller can neither grant nor refuse them. Requests are made to the platform concerned: on iOS via reportaproblem.apple.com, on Android from the Google Play order history. The Seller nonetheless remains available at contact@derja.fr to help the Customer with the process.
11. Force majeure
The Seller cannot be held liable for non-performance or late performance of its obligations in the event of force majeure within the meaning of article 1218 of the French Civil Code.
12. Legal guarantees
The Customer benefits from the legal guarantee of conformity (articles L224-25-12 et seq. of the French Consumer Code) for digital content. In the event of non-conformity, the Customer may contact the Seller at contact@derja.fr.
13. Mediation and dispute resolution
In the event of a dispute not resolved with customer service, the Customer may use a consumer ombudsman free of charge:
CNPM: Médiation de la Consommation
27 avenue de la Libération, 42400 Saint-Chamond, France
Website: https://www.cnpm-mediation-consommation.eu
European online dispute resolution platform: https://ec.europa.eu/consumers/odr/
14. Archiving
Orders above €120 are archived by the Seller for 10 years in accordance with article L213-1 of the French Consumer Code. The Customer may request access to these archives at contact@derja.fr.
15. Governing law and jurisdiction
These Terms are governed by French law. Disputes fall within the jurisdiction of the French courts, subject to the mandatory provisions applicable to the consumer in their country of residence. For business customers, see article 18.11.
16. Contact
Email: contact@derja.fr
Post: Ismael Dubuc, 30 Allée Sidney Bechet, 93430 Villetaneuse, France
17. Payment provider details
Stripe, Inc.
354 Oyster Point Blvd, South San Francisco, CA 94080, USA
18. Business customers (Derja for teams)
18.1 Scope
This article governs the “Derja for teams” offer, reserved for companies, international organisations, associations, NGOs, educational institutions and other bodies that buy it for their business purposes, for the benefit of people they designate (hereinafter “the Organisation” and “the Beneficiaries”). It prevails over the Organisation's purchasing terms, unless the Seller agrees otherwise in writing.
18.2 Order and formation of the contract
The Organisation places its order by email to contact@derja.fr, stating its name, its billing address, its VAT number if it has one, and the number of Beneficiaries. The Seller sends it an invoice. The contract is formed when this invoice is paid, which constitutes acceptance of this article.
18.3 Price
The price is €30 excluding tax per Beneficiary per year, for an order of at least 5 Beneficiaries. VAT not applicable, art. 293 B of the French General Tax Code: the amount invoiced is therefore €30 per Beneficiary. A Beneficiary added during the year is invoiced at the same price, for one year from their activation. The applicable price is the one on the invoice.
18.4 Invoicing and payment
The invoice is issued in euros and payable online, on receipt, no later than 30 days after its issue date. No discount is granted for early payment.
18.5 Late payment
In accordance with article L441-10 of the French Commercial Code, any late payment automatically incurs, from the day after the due date and without prior reminder, late-payment penalties at three times the French statutory interest rate in force, together with a fixed compensation of €40 for recovery costs (article D441-5 of the French Commercial Code). If the recovery costs incurred exceed this amount, the Seller may claim additional compensation, on proof. For a public-sector buyer, the payment-term and late-interest rules of French public procurement apply instead of this article.
18.6 Activation and duration
Each Beneficiary creates a free Derja account with the email address that the Organisation sends to the Seller. The Seller switches on Derja+ for each account within two working days of payment of the invoice and receipt of the list of addresses, whichever is later. If an address matches an account that already has a paid subscription running, the Seller informs the Organisation before any activation.
Access lasts one year from its activation and ends on its own at the end of that period, with no automatic renewal. The Seller informs the Organisation before the end date; a renewal is a new order. When access ends, each Beneficiary keeps their account and their progress, on the free version.
18.7 Personal access
Each access is personal and tied to one Beneficiary's account: it cannot be shared between several people. Each Beneficiary accepts the Terms of Use when creating their account, of which they remain the sole holder. The Organisation informs the Beneficiaries of the access offered to them.
18.8 Personal data
The Organisation sends the Seller the Beneficiaries' email addresses for the sole purpose of activating their access, and makes sure they are informed of this. The Seller passes no data about the Beneficiaries' use of the service to the Organisation: it only confirms the addresses activated and the end date of their access. The Beneficiaries' data is processed in accordance with the Privacy Policy.
18.9 Refunds
No refund is granted for an access that has been activated. The Seller may nonetheless, as a commercial gesture and at its discretion, grant a partial refund in the event of a technical problem attributable to the service that made it unusable for a significant period.
18.10 Liability
The Seller is bound by an obligation of means. Its liability, for all causes combined, is limited to the amount paid by the Organisation for the order concerned. It is not liable for indirect damage, such as operating loss or loss of revenue.
18.11 Governing law and disputes
The contract is governed by French law. The parties first seek an amicable solution. Failing agreement within 30 days, the dispute is brought before the French court with jurisdiction under the ordinary rules.