For Landlords of Apartments and Single-Family Homes
We'll help you gather the necessary information and documents, and use them to prepare your utility bill statement, including the cover letter. You gather the information, and Florian will guide you step by step through the process.
The chat and the preparation are free. An order is not placed until you pay via the payment link—for example, by credit card. A WhatsApp message alone does not trigger a chargeable order.
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So you can have the evening off
The lease agreement is in the emails, and the service charge statement is in the folder. In addition, there is information about your tenant's advance payments.
You don't have to have everything completely put together right from the start. However, the information you need must be easy to find. For example, look through your file folder for documents and take photos of them, send screenshots, or type the details into a message. Florian will help you keep track of everything.
Instead of a long list to fill out yourself, you'll get the next relevant question.
Send us the photo, and we'll check to see if the information is legible and what else is needed.
You'll stay in WhatsApp and won't need any additional billing software or a new portal.
Prepare for free, then decide
Tell Florian what you're renting out, or ask your questions first. To get everything ready, he'll ask you for the necessary information and documents. You don't have to have everything ready just yet; you can submit any missing information later.
Find the necessary information and send clear, legible photos, PDFs, or screenshots. You can also provide details via voice message. Florian will follow up if anything is missing; please submit any required supporting documents at that time. The preparation and document review are free of charge.
Once everything is ready, you’ll receive a payment link. The fee for creating the document is €50 (including VAT) per billing statement and lease agreement. You place the order only after you pay via the link—for example, by credit card. Simply agreeing to the order in the chat does not trigger a chargeable order.
You will receive the audited statement along with a friendly cover letter and the calculated advance payments for the following year. After reviewing the documents, please forward them to your tenant.
The final step has already been prepared as well
A completed calculation alone won't save you all the work. That's why we also provide you with the Complete letters to your tenant – phrased in a friendly way and appropriate for your relationship.
The assistant asks whether you use the informal "du" or the formal "Sie." The letter explains the results of the billing and includes the Calculation of Monthly Advance Payments for the Following Year.
You'll receive the invoice and cover letter together, with the appropriate personalized greeting. That way, you won't have to write a letter yourself at the end.
Please find attached your utility bill. In the cover letter, we explain the results and how your monthly advance payments for the coming year were calculated.
Best regards
Sample Excerpt · The final letter will include your specific amounts.
Performance & Price
Chat, preparation, and document review are free of charge. Once everything is ready, you’ll receive a payment link. Only after you make your payment will you be commissioning our team to prepare the documents. For €50 (including VAT) per statement and lease agreement, you’ll receive the reviewed statement along with a personalized cover letter and calculated advance payments for the following year.
Florian, your AI assistant, will help you gather the necessary documents. Afterward, a data4success GmbH employee will prepare and quality-check your statement.
Including sales tax per billing cycle and lease agreement
No additional fee for a change of tenant
Clicking here starts the free chat. The order will not be placed until you pay via the payment link later.
For your private rental
Whether you live in an apartment or a house: We'll let you know via chat which documents you need for your billing.
The statement for your tenant is generated based on the property management statement and your other documents.
Invoices, notices, and payment details: We'll help you put together the basics for your rental property.
The documents listed are examples. We’ll clarify what you need for your specific situation via chat. We’re happy to provide a customized quote for entire apartment buildings. Please describe your situation in WhatsApp and ask for a staff member to review it.
Renting Fits Into Your Life
Whether it's your first investment or a property you've been renting out for years: If you'd like to spend your time doing something else, you can hand over the management of the property.
27 · First Condo
Anna had rented out her first apartment. When it was time to prepare the first statement, she didn't know what documents were required—and didn't want to learn how to use new software just for that.
34 · Landlords as a Side Job
In addition to his full-time job, Daniel invested in real estate and had his receipts scattered among emails and folders. He wanted to know how to get started with his bookkeeping.
46 · Very busy at work
Julia's workdays were busy, and her time after work was precious. She wanted to hand over the statement of account, along with a friendly cover letter, to her long-time tenants.
Get this done before the end of the year
Thanks to our streamlined preparation process, we can process even last-minute settlements within the current calendar year. Start the document review and let us know your deadline—we’ll determine whether we can complete the work in time.
Last-minute appointments are possible, but there is no blanket guarantee of availability: this depends on the completeness of the documentation, the nature of the case, and available capacity. Be sure to allow time for access to the tenant's property.
For example: Fiscal year 2025
By that time, the statement for the period January 1–December 31, 2025, must generally have been received by your tenant.
Anyone who files their tax return late risks having to pay additional taxes. Once the twelve-month period has expired, additional claims are generally barred—unless the landlord is not at fault for the delay.
Would you rather talk about it first?
Would you like to know how the service works or if your situation qualifies? Call this number to reach Florian, the same AI assistant as on WhatsApp.
Florian is an AI assistant. He'll help you get to know the service and figure out your next steps.
You can have the process explained to you over the phone. You’ll still need to send the lease agreement, statements, and other documents via WhatsApp—Florian will guide you through the preparation process there.
Any more questions?
The most important things to know before sending your first message.
No. The chat and the preparation are free. Neither opening WhatsApp nor your messages nor confirming your interest in the chat will trigger a paid order. Once everything is ready, you’ll receive a payment link. The order is only placed once you pay through that link—for example, with a credit card.
You don't need to know in advance which documents are required, and you don't have to have everything fully prepared yet. Florian will ask for the information and documents step by step. You can gather the information—for example, from your emails or a file folder—and send clear, legible photos, screenshots, or PDFs. You can also record the information verbally; however, the required supporting documents must still be provided. Our team is here to help if anything is unclear.
Yes. You can send clear photos, PDFs, and screenshots—even from your banking app. You can explain the context via voice message. If any supporting documents are needed for the settlement, the assistant will ask for them separately.
You'll find out what information or documents are still needed for the preparation. You can submit any missing documents later. Our team may also have questions during the final review.
The chat, guided preparation, and document review are free of charge. Once everything is ready, you’ll receive a payment link. Only when you pay through that link—for example, by credit card—do you place an order for the document to be created. Messages in the chat alone are not sufficient for this.
The fee for preparing each statement is €50, including VAT, per statement and lease. For two leases and two requested statements, the total is 2 × €50, or €100. There is no additional charge for a change of tenant. You will receive an invoice showing the VAT.
The AI helps gather and prepare the information. An employee of data4success GmbH then takes over the creation and quality assurance process. The AI assistant is available around the clock; personal contact is available on weekdays between 9 a.m. and 3 p.m.
Yes, we'd be happy to provide you with a customized quote for an entire apartment building. Please describe your situation in as much detail as possible on WhatsApp and specifically ask for a representative to review your case. That way, we can work with you to determine the appropriate scope of work and price.
Yes. As specialists in data integration, we can design customized processes—even for thousands of units—that automate reports and billing based on your DATEV data. We’ll work with you to determine which data and interfaces are needed for this.
Reporting is our specialty. We can also help you analyze the returns and costs of your portfolio. To receive a personalized quote, please use the "Contact" button in the upper right corner to schedule a Teams meeting.
We do not charge an additional fee for the change of tenant itself. However, the €50 (including VAT) applies per billing cycle and tenancy.
Here’s an example: One tenant lives in your apartment from January through June, and the next one from July through December. If we’re to prepare a statement for both tenancies, you’ll order two statements at €50 each, for a total of €100. Florian will ask for the respective rental periods and the necessary information, such as any interim meter readings.
Thanks to our efficient preparation, we can also handle requests on short notice. Before accepting an assignment, our team will determine whether we can meet your deadline based on the documents, the nature of the case, and our available capacity. Important: For calendar-year billing, the deadline for the previous year generally ends on December 31 of the following year. What matters is that the tenant receives the documents on time—not just that they are prepared or sent.
Yes. You’ll receive the statement along with a complete, friendly cover letter and a breakdown of the advance payments for the following year. The assistant will ask how you’d like to be addressed: informally (using “du”) or formally (using “Sie”). You’ll review the completed documents and send them out yourself.
The provider is data4success GmbH. The servers we use for this service are located in Frankfurt am Main. You use WhatsApp for communication; WhatsApp’s privacy policy also applies to the processing of data through WhatsApp. The location information does not constitute a guarantee that WhatsApp processes all data exclusively in Frankfurt. You can find information on the processing of personal data in our Privacy policy. Please send only the documents required for your application.
Yes. Under 06051 78 97 03 4 Florian, our AI assistant, will explain the service and the process to you. You can then send the required documents via WhatsApp; they are not submitted over the phone.
Start with your first message
Ask Florian your first question or tell him what you're renting out. To prepare, gather the necessary information and send it to him step by step as a photo, screenshot, PDF, or voice message.
The chat and preparation are free. The setup fee is €50 (including VAT) per billing cycle and lease agreement. Only your payment via the payment link confirms the order—not your messages in the chat.
The People Behind Your Utility Bill Service
That is also the idea behind data4success. We help medium-sized companies use AI to process and integrate data and make it analyzable. This enables managers to better manage their departments, costs, and prices.
Using Power BI, Microsoft Fabric, and appropriate AI solutions, we create a reliable basis for decision-making from distributed information and automate repetitive tasks.
Compare revenue, understand costs, improve margins: We help you use your data to answer the right questions. For real estate as well, you can calculate portfolio returns and analyze revenue and costs across multiple properties.
You can take advantage of this advisory service regardless of your utility bill.
