Only the German version of the terms & conditions shall apply. The English version is only a convenience translation.
Version 31.07.2025
1.1 Scope of application
These general Terms and Conditions for the Supply of Electricity ("T&C") govern all business relationships for the supply of electricity between the respective contracting customer and Ostrom GmbH.
1.2. Which company is Ostrom?
Ostrom is a brand of Ostrom GmbH. Ostrom GmbH is your contractual partner and is hereinafter also referred to as "Supplier", "Ostrom" or with the words "us" or "we".
1.3. Who can conclude a contract with Ostrom?
A contract with Ostrom can be concluded by private individuals and companies who use the electricity for their own needs. Ostrom reserves the right to limit the maximum permitted annual consumption for new registrations. We may refuse to conclude a contract.
1.4. How can I conclude a contract with Ostrom?
An order for electricity supply to Ostrom can be sent online via the Ostrom website (www.ostrom.de). Alternatively, the order can also be placed via the mobile application provided by Ostrom, via comparison portals or via our sales partners. A contract is only concluded when the order is confirmed by us and we have notified you of the start of delivery, but no later than the start of delivery of electricity. A prerequisite for the contract confirmation is the completion of the supplier switch process (§ 20a EnWG), i.e., that Ostrom has, in particular, received confirmation of the termination of your previous electricity supply contract as well as confirmation of the supplier switch from the network operator.
1.5. Does Ostrom carry out a credit check?
We can check the creditworthiness of a new customer. We can use external service providers for this and comply with current data protection legislation.
1.6. As a customer, can I revoke my contract?
Yes, you can cancel your contract informally up to fourteen days after conclusion of the contract without giving reasons. The revocation instructions and a revocation form that you can use for this can be found under no. 8.
1.7. How long does my contract run for and how can I cancel it?
The contract is concluded for an indefinite period and can be terminated by either party at any time in text form with two weeks’ notice. Simply use our contact form or the cancellation feature in the Ostrom app. The effective date is the date we receive your notice of termination. You can also cancel via our website at ostrom.de/kuendigung-cancellation; in this case, the termination and its confirmation are governed by the provisions of § 312k BGB.
1.8. When can the contract be terminated without notice?
We have the right to terminate the contract without notice for good cause. Such a reason exists in particular if you deliberately make false statements about the essential characteristics for determining the advance payment, or if you fail to meet your payment obligation despite repeated reminders. In the latter case, we must give you two weeks' notice of termination.
1.9. How does communication with Ostrom work?
As a digital electricity provider, communication with us takes place exclusively via digital communication channels (e.g. Email, via the Ostrom app or the contact form). Upon conclusion of the contract, you undertake to inform us immediately of any changes of your email address.
2.1. Who supplies the electricity at Ostrom?
The electricity supplied by Ostrom is provided by SüdWestStrom. We may also use third parties to fulfill our contractual obligations.
2.2. When does the supply of electricity by Ostrom begin?
Ostrom delivers electricity as quickly as possible. The start of delivery depends on numerous external factors, such as the date of termination of your old contract and the approval of the grid operator. If you have specified a later start date for the delivery period, this will apply. We will inform you of the exact start of delivery. If the start of delivery is only possible more than two months after receipt of the order, both parties have the option of terminating the contract in text form without notice.
2.3. What quality of electricity does Ostrom supply?
You receive low-voltage electricity, with the exact type of electricity and frequency depending on your local grid.
2.4. What happens in the event of a malfunction? What is the liability?
2.4.1. We are exempt from the obligation to perform if an interruption or irregularity in the power supply is the result of a disruption to the grid operation, including the grid connection. In this respect, we are also exempt from liability. This does not apply if the interruption is due to unauthorized measures on our part.
2.4.2. In such a case, you may be entitled to make claims against the grid operator. At your request, we will inform you of the reasons for an interruption or irregularity caused by the grid operator. The prerequisite for this is that the reasons are known to us or can be clarified in a reasonable manner.
2.4.3. We shall also be released from our obligation to perform if we are prevented from supplying electricity due to force majeure or other circumstances which we are unable or cannot reasonably be expected to eliminate.
2.4.4. Otherwise, our liability is limited to intent and gross negligence. This does not apply to the breach of essential contractual obligations or damages resulting from injury to life, limb or health.
2.4.5. In the event of slight negligence, compensation for the breach of material contractual obligations shall also be limited to the foreseeable damage typical of the contract.
2.5. As a customer, am I allowed to operate my own systems for electricity generation?
Yes, you may operate your own systems.Own systems are used for the decentralized generation of electricity.
3.1. What happens during a move?
3.1.1 If you move, you can apply for the contract to be continued at the new delivery point. To do this, you must inform us of the date of your move, your new delivery address and your new meter number.
3.1.2. Alternatively, you can terminate the contract with notice. In this case, you must also inform us of your future address. If you fail to do so, you will be liable for any resulting damages.
3.2. What happens when I change supplier?
In the event of a change of supplier, we shall comply with our obligations to cooperate promptly and free of charge.
4.1 How is the electricity supply remunerated?
4.1.1. The net fee to be paid by you consists of the monthly "basic fee", the consumption-dependent "unit price" per kWh and the monthly "grid fees". The respective amount is agreed when the contract is concluded. If there is a price change at a later date, the changed price replaces the previously agreed price. The gross price is calculated from the net price plus the statutory VAT at the applicable rate.
4.1.2. As a customer, you are obliged to pay for the electricity supplied.
4.2. Where can I get more information about the applicable tariffs?
You can view the latest information via the Ostrom app. The app is available in the Apple App Store and Android Play Store. You will also receive important information by email. If you have any questions, you can reach us via the contact form.
4.3. How are the net unit price and the net basic fee made up and under what circumstances can they change?
4.3.1. The relevant calculation factors for the components of the "unit price" are:
- Costs for the purchase (including generation) of electricity
- Marketing and sales
- Electricity tax
- Variable grid fees
- Concession fees
- Levy in accordance with the Combined Heat and Power Act (CHP levy)
- Levy in accordance with Section 19 (2) Strom NEV (Section 19 StromNEV levy)
- Levy according to § 17f. EnWG (offshore grid levy)
- Levy in accordance with Section 18 of the Ordinance on Disconnectable Loads (levy for disconnectable loads)
- Certificates of origin
- Credit defaults
- Miscellaneous
4.3.2. The relevant calculation factors for the components of the monthly basic fee are as follows:
- Marketing and sales
- Miscellaneous
4.3.3. The relevant calculation factors for the components of the monthly fee "Network charges" are:
- Grid fees
- Metering point operation (please note no. 4.3.8)
4.3.4. The components may change at any time - in particular on the basis of new statutory regulations - which are then also taken into account accordingly in the pricing.
4.3.5. Ostrom offers variable tariffs (in particular the SimplyFair tariff and its current sibling tariffs SimplyFairSpeicherheizungElectricity, SimplyFairHeatpumpElectricity, SimplyFairHeatpump, and SimplyFairSpeicherheizung, as well as the SimplyDynamic tariff), which are based on current market prices. These tariffs do not include a price guarantee. In the event of rising costs, we are entitled—and in the event of falling costs, we are obliged—to adjust the unit price and/or the basic fee at our reasonable discretion in accordance with § 315 BGB. When determining a price change, Ostrom is obligated to take cost increases into account only after offsetting any opposing cost reductions, and to balance cost increases and reductions, unless this is excluded for regulatory reasons. Ostrom ensures that the amount and timing of the price change are determined in such a way that cost reductions are reflected using the same objective standards as cost increases. You may have the exercise of reasonable discretion reviewed in accordance with § 315 (3) BGB.
4.3.6. A price change shall only become effective for you upon notification from us in text form. You must receive the notification at least one month before the intended date of change. In this case, you have the right to terminate the contract in text form without notice. We will inform you of this accordingly in the notification. Price changes can also be made before the start of the electricity supply, but at the earliest after the conclusion of the contract.
4.3.7. The above rules also apply insofar as new taxes, levies, surcharges, grid fees, or other government-imposed charges or reliefs come into effect in the future, which affect the procurement, generation, storage, grid usage (transmission and distribution), or consumption of electrical energy.
4.3.8. Our prices include the costs for your measuring point up to 20.00€ per year. We will invoice you separately for any costs in excess of this.
4.4. How is the electricity supplied metered?
4.4.1. In compliance with the Metering Point Operation Act, the electricity supplied by us is measured using your meter readings. This can be done by us, the grid operator, the metering point operator or by you as the customer. Readings are taken for the purpose of billing, in the event of a change of supplier or if we have a legitimate interest in the reading.
4.4.2. You are obliged, after prior notification, to allow the authorized representative of the grid operator, the metering point operator or the supplier access to your property and your premises, insofar as this is necessary for meter reading.
4.4.3. If we require you to read the meter yourself, we will notify you of this in good time. You can object to this in individual cases if this is not reasonable for you. In the event of a self-reading, you can communicate the meter reading via the Ostrom app and the contact form.
4.4.4. In the event that you have not submitted a meter reading despite timely notification, the authorized representative has been denied access or no plausible meter reading is available for other reasons, we may estimate your consumption. The basis for this estimate may be the last consumption determined by meter reading or the consumption of comparable customers, taking appropriate account of the actual circumstances.
4.5. How is the electricity supplied billed?
4.5.1. Electricity consumption is billed once a year. If there is a different agreement with you, this shall take precedence. If the contract ends within a billing period, billing will take place immediately.
4.5.2. The quantity of electricity consumed determined in accordance with No. 4.4 is multiplied by the energy price.
4.6. Automatic Switch to the Dynamic Electricity Tariff
4.6.1. Ostrom is entitled to switch the agreed tariff to the dynamic electricity tariff (SimplyDynamic), provided that a smart meter (iMsys) is installed at your home and your consumption data is fully and continuously transmitted to Ostrom by the metering point operator. After the switch, the supplementary terms and conditions of Ostrom GmbH for the dynamic tariff (SimplyDynamic) will apply.
5.1. When are my invoices and advance payments due?
5.1.1. Invoices and advance payments are due on the date specified by us, but no earlier than two weeks after receipt of the request for payment. Objections to this shall only entitle you to defer or refuse payment to us if there is a serious possibility of an obvious error or if the consumption stated in an invoice is more than twice as high as the comparable consumption in the previous billing period for no apparent reason. In the latter case, this only applies as long as a verification requested by you has not established that the metering device is functioning properly.
5.1.2. You may only offset claims to which we are entitled with undisputed or legally established claims.
5.2. Can Ostrom require deposit payments from me?
5.2.1. Ostrom may require deposit payments for the electricity supplied during the billing period. The amount of the deposit payment is calculated proportionally for the prepayment period based on the consumption in the most recently billed period. If such a calculation is not possible, the deposit payment is based on the average consumption of comparable customers. We determine this using customer-specific characteristics, such as the number of people in the household, the size of the apartment, or the presence of particularly power-intensive equipment. You are obligated to provide such information truthfully. If you, as a customer, credibly demonstrate that your consumption is significantly lower, we will take this into appropriate account. In the event of a price change, we are entitled to adjust the deposit payment accordingly; the adjustment will not take effect before the price change becomes effective.
5.2.2. If the prices change within a billing period, the consumption relevant for the changed prices shall be calculated pro rata temporis. Seasonal fluctuations in consumption shall be appropriately taken into account on the basis of empirical values for comparable customers. The same shall apply in the event of a change in the VAT rate or other taxes and duties.
5.2.3. If the advance payments made differ from the amount resulting from the invoice, we will reimburse you for the excess amounts paid immediately, at the latest within two weeks, or the shortfall must be paid by you as the customer. If you have issued us with a SEPA direct debit mandate, we will refund the overpayments to your current account specified in the SEPA direct debit mandate or debit any shortfalls from it.
5.3. How can I pay with Ostrom?
You can pay by SEPA direct debit mandate or by bank transfer.
5.4. What happens if I don't pay on time?
If collection by SEPA direct debit mandate is not possible at the time specified by us according to the calendar or if we have not received your transfer by the time specified by us in accordance with Section 5.1.1, you will be in default. We have the right to claim interest on arrears and compensation for the damage caused by the delay in accordance with the statutory provisions, in particular also costs for SEPA return debits.
6.1. What bonuses does Ostrom offer?
As part of our bonus program, we offer bonuses for new customers (hereinafter referred to as "new customer bonus"), existing customers who refer new customers (hereinafter referred to as "referral bonus"), and customers who connect qualifying devices to their Ostrom account (hereinafter referred to as "connect bonus"). Our bonus programs and rewards are voluntary and additional benefits. We reserve the right to change or terminate such promotions at any time.
6.2. What is a new customer bonus and who gets it?
6.2.1. For offers with a new customer bonus, we will grant you a credit if you have not been an Ostrom electricity customer within the last 6 months, sign an electricity contract with us and remain our customer for at least 11 months at the same meter. You will be shown in the order process whether a new customer bonus is granted.
6.2.2. The new customer bonus is a one-off bonus that cannot be combined with other Ostrom promotions.
6.2.3. The exact details are set out in the electricity supply contract concluded between you and us or in a separate agreement.
6.3. What is a referral bonus and who gets it?
6.3.1. The Customer Referral Program ("Referral Program") is a program of Ostrom through which existing customers of Ostrom can receive rewards by referring new customers to Ostrom. A referring existing customer (in each case the "Referrer" or "Advertiser") participates in the Referral Program by referring new customers to Ostrom in accordance with the conditions of participation set out herein. All Ostrom employees are excluded from participation.
6.3.2. We provide each advertiser with a personal number sequence ("referral code").
6.3.3. The referral code may not be shared on internet platforms. In such cases, we reserve the right to limit the validity of the referral code.
6.3.4. By using the procedure of this advertising program, the advertiser agrees to these conditions of participation.
6.3.5. The advertiser is free to choose the technical medium it uses to transmit the referral code. The advertiser undertakes Ostrom to obtain the consent of the respective recipient before each transmission of a referral code. In the event that recruited new customers assert claims against Ostrom due to the unsolicited sending of the referral code, the advertiser shall indemnify Ostrom against all claims in connection therewith and reimburse the costs of a reasonable legal defense. Ostrom reserves the right to assert further claims against the advertiser arising from this situation. In the event of non-compliance with this obligation, the Advertiser concerned shall be excluded from participation in the advertising program with immediate effect.
6.3.6. New customers can enter the referral code of an advertiser in a field provided for this purpose when concluding a contract with Ostrom.
6.3.7. Successful placement is deemed to have taken place if the following requirements are met cumulatively:
a. The recruited new customer concludes an electricity supply contract with Ostrom, the supply of electricity actually begins and the recruited new customer becomes an Ostrom customer.
b. During the application process, the new customer referred has specified the referral code of an advertiser in accordance with No. 6.3.6.
c. The new customer has not been an Ostrom electricity customer in the 12 months prior to the conclusion of his/her electricity supply contract.
d. The advertiser still has an active electricity supply contract with us at the time of payment.
e. It is the sole responsibility of the advertiser to ensure that the new customer recruited follows the procedure described in point b when concluding the contract. If the procedure is not followed, this does not constitute a successful referral.
6.3.8. The referral bonus will be credited to the advertiser after a period of three months, beginning with the delivery of electricity to the new customer, provided that all conditions under No. 6.3.7. are met. The terms of 6.2 apply to the credit of the new customer. The credit is regulated in No. 6.5. The reward cannot be combined with other Ostrom promotions. We are entitled to offset your claim to payment of the referral bonus against outstanding claims against you.
6.3.9. The exact details are set out in the electricity supply contract concluded between you and us or in a separate agreement. We reserve the right to terminate such promotions at any time or to limit the number of new customers for whom you can receive a referral bonus.
6.4. What is a connect bonus and who gets it?
6.4.1. For offers with a connect bonus, customers must connect a qualifying device within 11 months of their contract delivery start date. Ostrom will verify the connection status exactly 11 months after the delivery start date. The connection must be active on this date to qualify. If the connection was active before but is no longer active at the time of the check, it will not qualify. Additionally, the customer must have an active electricity contract with Ostrom at the time of the check.
6.4.2. Qualifying devices include:
- Smart devices such as EVs, chargers, HVAC systems, solar panels, or batteries, as indicated and supported for connection in the Ostrom mobile app.
- Ostrom supports only a limited range of devices, brands and models, which may change over time. While Ostrom makes efforts to advertise supported devices accurately, errors may occur, and advertised devices might not always be compatible.
6.4.3. Ostrom facilitates ways to connect devices but cannot guarantee successful connections. Customers are responsible for ensuring their devices connect successfully. If the connection is not successful, the connect bonus will not be granted.
6.4.4. The exact details are set out in the electricity supply contract concluded between you and us or in a separate agreement. We reserve the right to terminate or change such promotions at any time.
6.5. How are bonuses credited?
6.5.1. As soon as the requirements for the new customer bonus pursuant to No. 6.2, the referral bonus pursuant to No. 6.3, or the connect bonus pursuant to No. 6.4 have been met, the bonuses will generally be credited to your Wallet. In exceptional cases (in particular if the use of the Wallet is not permitted due to third-party conditions), we reserve the right to credit the bonus by other means.
6.5.2. You can credit credit from the wallet to your next invoice in the Ostrom app (option 1) or convert it into an Ostrom Store voucher (with a higher value than the credit, if applicable) (option 2). The selection of one of the two options cannot be changed afterwards.
6.6. How does the prize draw work?
6.6.1. Ostrom records all successful referrals of an advertiser in the course of a month.
6.6.2. At the end of the month, all referrers who have successfully referred at least one person in that month will be entered into a prize draw.
6.6.3. The type and number of prizes awarded is at the discretion of Ostrom. There is no legal entitlement to a prize.
6.6.4. The advertisers who receive a bonus will be named on the Instagram profile "ostrom.de" and on the website www.ostrom.de if they have given their consent to this when participating in the advertising program.
7.1. Based on your consent during the contract sign-up process, Ostrom has the right to order an intelligent metering system (iMsys) from the responsible grid operator or the designated metering point operator on behalf of the customer. Ostrom will only order an iMsys if this does not result in any additional costs for the customer. If the customer orders an iMsys directly through Ostrom, the dedicated Smart Meter T&C apply. Once the iMsys is installed, Ostrom is entitled to switch the contract in accordance with section 4.6.
7.2. For customers with an iMsys, Ostrom has the right to adjust the tariff application profiles (Tarifanwendungsfälle, TAF) on behalf of the customer.
8.1. Right of revocation
8.1.1. You have the right to revoke the energy contract within fourteen days without giving any reason.
8.1.2. The revocation period is fourteen days from the date of the conclusion of the contract.
8.1.3. To exercise your right of revocation, you must inform us, Ostrom GmbH, Strassburger Strasse 55, 10405 Berlin, Email: widerruf@ostrom.de, of your decision to revoke from the contract by an unequivocal statement (e.g. a letter sent by post or email). You can use the sample revocation form attached under no. 8.3. for this purpose, but this is not mandatory.
8.1.4. To meet the revocation deadline, it is sufficient for you to send your notification of exercising your right of revocation before the revocation period has expired.
8.2. Consequences of revocation
8.2.1. If you revoke from this contract, we shall reimburse to you all payments received from you, including the costs of delivery (with the exception of the supplementary costs resulting from your choice of a type of delivery other than the least expensive type of standard delivery offered by us), without undue delay and in any event not later than 14 days from the day on which we are informed about your decision to revoke from this contract. For this repayment, we will use the same means of payment that you used for the original transaction, unless expressly agreed otherwise with you; in no case will you be charged any fees for this repayment.
8.2.2. If you have requested that services or the supply of electricity should commence during the revocation period, you shall pay us a reasonable amount corresponding to the proportion of the services already provided up to the time you inform us of the exercise of the right of revocation with regard to this contract compared to the total scope of the services provided for in the contract.
8.3. Sample revocation form
(If you want to cancel the contract, please fill out this form and send it back to us).
Ostrom GmbH
Strassburger Strasse 55
10405 Berlin
Email: widerruf@ostrom.de
- I/we (*) hereby revoke the contract concluded by me/us (*) for the purchase of the following goods (*)/the provision of the following service (*).
- Ordered on (*)/received on (*)
- Name of the consumer(s)
- Address of the consumer(s)
- Signature of the consumer(s) (only for notification on paper)
- Date (*)
(*) Delete as appropriate
9.1. How is my personal data processed?
You can find all the information on https://www.ostrom.de/privacy-policy.
9.2. Can these T&C change?
9.2.1. We are entitled to amend these Terms and Conditions if an unforeseeable change in the legal or factual situation occurs for you or for us—beyond our control—which significantly distorts the balance between performance and consideration under this contract or creates a gap in the contract that leads to substantial difficulties in its execution. This may be the case in particular if one or more clauses in these Terms and Conditions become invalid or risk becoming invalid due to a change in legislation or a final court ruling, and the agreed balance cannot be maintained by applying a statutory provision. The Terms and Conditions will only be amended to the extent necessary to restore that balance or to close the contractual gap, and only if the amendment is reasonable for you.
9.2.2. For any changes to these Terms and Conditions to take effect, we must inform you at least one month in advance, in text form, about the changes and about your rights under section 9.2.3.
9.2.3. If the Terms and Conditions are amended, you have the right to terminate the contract with us without notice, in text form, effective at the time the changes take effect.
9.3. Which law applies to the contract?
The contractual relationship with you is governed by the law of the Federal Republic of Germany.
9.4. Can the contract be transferred from us to third parties?
We are entitled to transfer the rights and obligations arising from this contract to a legal successor or a third party. The transfer shall only become effective with your consent. Consent shall be deemed to have been given if the transfer does not result in a reduction in the security for you and you do not object in text form within six weeks of the written notification of the transfer of rights and obligations. Separate reference will be made to these consequences in the notification.
9.5. Do the German or English version of these T&C apply?
Only the German version of these T&C applies. The English version is for information purposes and simplification only. This applies regardless of which language is selected on the website.
9.6. I would like to complain about Ostrom - How can I do this?
You can contact us at any time using our contact form. We will be happy to work with you to find a solution.
9.7. What options are there for resolving a dispute?
9.7.1. In the event that we cannot find an amicable solution, you as a consumer within the meaning of Section 13 of the German Civil Code (BGB) can apply for arbitration proceedings at the Energy Arbitration Board.
9.7.2. Ostrom is obliged to participate in such proceedings. The limitation period is suspended upon submission of the application to the arbitration board. The contact details of the arbitration board are
Schlichtungsstelle Energie eV
Friedrichstrasse 133
10117 Berlin
Phone: 030-2757240-0
Fax: 030-2757240-69
Website: www.schlichtungsstelle-energie.de
Email: info@schlichtungsstelle-energie.de
9.7.3. Your right to appeal to a court remains unaffected by this.
9.7.4. You can find out about your rights at any time from the Federal Network Agency's consumer service:Consumer service of the
Federal Network Agency
P.O. Box 8001
53105 Bonn
Phone: 030-22480500
Email: verbraucherservice-energie@bnetza.de
9.8. How do I get information on maintenance services and charges?
You can obtain this information from your local network operator.
9.9. General information in accordance with the Energy Services Act
In connection with more efficient energy use by end customers, the Federal Office for Energy Efficiency maintains a list of energy service providers, providers of energy audits and providers of energy efficiency measures. Further information on the list of providers and the providers themselves can be found at www.bfee-online.de. You can also obtain comprehensive information on the topic of energy efficiency from the German Energy Agency.
Responsible Party
Ostrom GmbH
Strassburger Strasse 55
10405 Berlin, Germany
Contact form
We are legally represented by Matthias Martensen and Karl Villanueva.
Data Protection Officer
heyData GmbH
Gormann Straße 14
10119 Berlin, Germany
Email: info@heydata.de
You can find our additional Terms and Conditions here: ostrom.de/terms-and-conditions-overview.