In short and in plain language
Many trade websites show a price. Often it is only a rough figure. But customers easily read it as a firm promise.
There are three kinds of price. A guide price only helps you get a sense of the cost. A cost estimate is a careful forecast. A quote is binding on the business.
If the work will cost a lot more than estimated, the business must say so without delay. That is the law. The customer may then end the job.
So every price on the website needs a short note below it. The note says what kind of price it is. It also says what happens next.
We help you write these notes clearly on your website.
A customer enters the area, the material and a preferred date on your website, the calculator shows a range, and three weeks later work begins. On site the substrate turns out to be in poor condition, the effort grows, and the invoice ends up well above the figure the customer has in mind. Whether that stays an annoyance or turns into a dispute is often decided long before: by the words under the calculator result, in the enquiry form and in the cost estimate itself. In everyday German it is called a Kostenvoranschlag, in the statute a Kostenanschlag, and it is governed by one short provision, § 649 BGB. It sets out what applies when an estimate given without warranty is substantially exceeded, and it obliges the business to notify the customer without undue delay when an overrun is to be expected. This article separates the three kinds of price that appear on trade websites: guide price, cost estimate and binding quote. It shows which wording under a calculator result and in the form creates clarity, and what the duty to notify looks like as a routine inside the business.
Key takeaways
- Guide price, cost estimate and quote bind to different degrees: a business is bound by its quote (§ 145 BGB), a cost estimate given without warranty may be exceeded, and a guide price on the website promises no price at all.
- If a substantial overrun of the cost estimate becomes likely, the business must notify the customer without undue delay (§ 649(2) BGB). If the customer terminates for that reason, the business is paid only for the work done and its expenses.
- The statute sets no percentage for “substantial”. As a rule of thumb, the Verbraucherzentrale names a rise of more than 15 to 20 percent (Verbraucherzentrale); in a dispute, the individual case decides.
- Every calculator result needs four statements beneath it: that it is a non-binding guide price, what it is based on, what it leaves out, and that a cost estimate or quote follows only after measuring up or a site visit.
- In case of doubt a cost estimate is not to be paid for (§ 632(3) BGB). A business that charges for measuring up or preparing the estimate states the amount and the conditions in advance, on the website and in the enquiry form.
- Older templates cite § 650 BGB for the cost estimate. Since the reform of construction contract law the rule has stood unchanged in § 649 BGB; quote and form texts carrying the old number should be corrected.
Three kinds of price with different binding force
Prices appear on trade websites in three forms, and in conversation they are easily mixed up. The guide price is for orientation: a range per square metre, per appliance or per call-out, often the output of a price calculator. The cost estimate is a professional calculation for a specific job, with items, quantities and assumptions, but without any promise that the amount will hold in the end. The quote is the declaration that the business will do the work for a stated price. Anyone who offers to another to enter into a contract is bound by the offer, unless they have ruled out being bound (§ 145 BGB).
The German consumer advice centre, the Verbraucherzentrale, sums up the difference from the customer’s side: cost estimates are not binding, whereas businesses are as a rule bound by the prices in their quotes (Verbraucherzentrale). It also advises consumers to obtain two or three quotes or cost estimates from different firms before awarding a job (Verbraucherzentrale). So your estimate may well lie on the kitchen table next to others, and the customer compares amounts that can mean different things in law. A low cost estimate next to a higher fixed price looks cheaper, even though only one of the two amounts is a commitment.
| Feature | Guide price | Cost estimate | Quote with fixed price |
|---|---|---|---|
| Typical place | Pricing section of the website, output of a price calculator | Document after measuring up or a site visit | Document after measuring up, often with an acceptance period |
| Basis | Visitor’s own details, no inspection | Items, quantities and assumptions of the business | Scope of work described in full |
| Binding on the business | No price promised | Amount without warranty, may be exceeded | Bound by the price (§ 145 BGB) |
| If it costs more | What counts is what is agreed later | Notice of a likely substantial overrun (§ 649 BGB) | Extra effort without a change of scope is usually borne by the business |
| Cost to the customer | None | In case of doubt not to be paid for (§ 632 BGB) | Usually none, unless agreed beforehand |
The table shows why the wording on the website matters. A visitor does not distinguish between guide price and cost estimate if the page does not. If a calculator result says “Your price”, they read a promise. If it says “cost estimate” although nobody has been on site, the page claims more care than the figure contains. How ranges become dependable with a reference unit and a price date is covered in the article Showing prices on the website or not. This article is about the legal status of the figure.
A working aid, not legal advice
What § 649 BGB actually says
The provision has two subsections. Subsection 1 covers the case where a cost estimate was made the basis of the contract without the business warranting its accuracy, and it becomes apparent that the work cannot be carried out without substantially exceeding the estimate. If the customer terminates the contract for that reason, the business is entitled only to the claim under § 645(1) BGB (§ 649(1) BGB). That is a part of the remuneration corresponding to the work done, plus reimbursement of expenses not included in the remuneration (§ 645(1) BGB).
If such exceeding of the estimate is to be expected, then the contractor is to notify the customer without undue delay.
How much this means for the business becomes clear in comparison with free termination. A customer may terminate a contract for work at any time until the work is completed; the business then keeps its claim to the agreed remuneration but must allow for expenses it saves and for what it earns elsewhere instead. The presumption is that it is entitled to 5 percent (§ 648 BGB) of the remuneration for the part of the work not yet provided. Where the customer terminates because the estimate will be substantially exceeded, that share falls away: the work done and the expenses are paid, not the lost remainder.
Subsection 2 contains the duty that ultimately matters for the website. As soon as such an overrun is to be expected, the business must notify the customer without undue delay (§ 649(2) BGB). The BGB defines the term elsewhere as “without culpable delay” (§ 121(1) BGB). That does not mean at the end of the job or with the final invoice, but at the moment the deviation becomes apparent. If the notice is not given, that is a breach of duty, and for breaches of duty the law generally provides for damages, provided the business is responsible for the breach (§ 280(1) BGB). How such a claim turns out in an individual case depends on the circumstances.
What counts as a “substantial” overrun is left open by the statute; there is no fixed percentage. The Verbraucherzentrale names a rule of thumb: if the price rises by more than 15 to 20 percent (Verbraucherzentrale), the business must point this out. That is guidance from consumer advice, not a statutory value, and in a dispute the individual case decides. A business that sets an internal reporting threshold is on the cautious side with a figure below this rule of thumb. An early notice costs a phone call; a missed one may cost part of the remuneration.
Why older templates cite § 650 BGB
Anyone going through old quote templates, terms and conditions or website texts will often find § 650 BGB cited for the cost estimate. That was correct until the reform of construction contract law. The reform moved the provision, and the government bill already stated: “Der bisherige § 650 wird unverändert zu § 649 BGB-E.” – the former § 650 becomes § 649 unchanged (Bundestag printed paper 18/8486). The wording stayed the same; only the number changed. Today § 650 BGB governs the contract for work and materials (§ 650(1) BGB).
The old number has two consequences for the business. A customer who looks it up finds a different rule under § 650 and starts to doubt the rest of the text. And a text that cites a provision which has moved looks as if nobody has maintained it for years. The check is quick: search the quote template, the terms and conditions, the notes under prices, the form page and the FAQ for “§ 650” and, wherever the cost estimate is meant, change it to § 649.
Joineries, metalworkers and other businesses that make items to measure in the workshop should take a second look. Contracts for the delivery of movable things still to be produced are in principle governed by the law on sales. Where the things are not fungible, which usually means items made to measure, §§ 645, 648 and 649 BGB apply as well, among others (§ 650(1) BGB). A business making a railing or a cupboard on the basis of a cost estimate therefore has the same duty to notify.
The guide price on the website
A price calculator on the website produces a figure from the visitor’s details: area, material, access, preferred date. Nobody from the business has seen the property. A result like that is addressed to all visitors and is, as a rule, neither an offer that binds the business nor a cost estimate for a specific job. A calculation only becomes a cost estimate within the meaning of § 649 BGB when it is made the basis of the contract. Whether that has happened depends on what the customer had in writing before placing the order and what both sides referred to.
The risk therefore lies less in the calculator than in what happens next. If, after the enquiry, the business only sends a short email saying “Then we will get started” and the customer has nothing but the calculator result in front of them, it remains unclear which figure links the two. A business that writes its own cost estimate or quote after the site visit creates a clear basis and expressly replaces the guide price. This fits with what businesses themselves observe: 89 percent (Bitkom, 2025 survey) of the trade businesses surveyed report that their customers increasingly expect tailored offers.
Price law comes on top. Anyone who offers services to consumers or advertises them stating prices must give the total prices (§ 3(1) PAngV). For a guide price on a page aimed at private customers, that means VAT included, not net; how this works with a mixed clientele is covered in the article on showing prices on the website. And where a contract with consumers is concluded at a distance or off business premises, for example solely by email and phone or at the customer’s home, the law requires the total price in advance or, if it cannot reasonably be calculated beforehand, the manner in which the price is calculated (Art. 246a § 1 EGBGB). An hourly rate plus travel and materials at cost can be such a manner of calculation; a figure without explanation is not.
Wording under the calculator result
The result needs a short text beneath it that answers four questions and gives the price date. It sits directly under the figure, in the same type size as the rest of the text, not behind an asterisk at the bottom of the page. The following sentences are templates for the business to adapt to its trade:
- What the figure is: “Non-binding guide price based on your details. This is neither a quote nor a cost estimate.”
- What it is based on: “Calculated with the dimensions and material you selected above, assuming a normally accessible substrate.”
- What is missing: “Not included are disposal, scaffolding and work on the substrate that only becomes visible on site.”
- What comes next: “After measuring up you will receive a written cost estimate or a quote with a fixed price. Only that document applies.”
- Price date: “As of: month and year of calculation, amounts including VAT.”
| Wording on the page | How the customer may read it | Clearer version |
|---|---|---|
| Your price | as the promise of a fixed amount | Your non-binding guide price |
| Instant cost estimate online | as a cost estimate under § 649 BGB, although nobody has been on site | Instant guide price online, cost estimate after measuring up |
| Fixed price from … | as a fixed price for their own job | Guide price from …, with reference unit, scope and price date beneath |
| No hidden costs | as ruling out any overrun | What is not included is stated directly under the amount |
| Prices plus VAT on a page for private customers | as an incomplete price statement | Amounts including VAT (§ 3 PAngV) |
| Non-binding, as the only word | as a sign that everything is open, including the scope | Non-binding guide price; only the written quote is binding |
Notes in the enquiry form
The enquiry form is the second place where the level of commitment is settled, often without anyone noticing. A sentence above the send button helps decide what the customer expects after sending: a call back, an appointment, a cost estimate or a job already placed. Which fields a trade enquiry form needs is covered in the article How many fields an enquiry form can take. This section is about the sentences next to them.
The first sentence says that sending the form does not yet place an order. The second says what follows, for example: “We will get in touch, arrange an appointment to measure up and then send you a written cost estimate.” The third clarifies whether the cost estimate costs anything. Here the law is on the customer’s side: in case of doubt a cost estimate is not to be paid for (§ 632(3) BGB). A business that wants to charge for measuring up, planning or an extensive estimate has to agree that in advance, and the website is the first place where the customer learns about it. Whether the amount is credited against a later order belongs in the same sentence.
Type of statement
Guide price, cost estimate or quote, named explicitly. One term per place, used the same way across the whole website.
Basis
Which details went into the figure and which assumptions the business makes, for example about the substrate or access.
Not included
Items that are often added, such as disposal, scaffolding or preparatory work. Naming them beforehand beats explaining them later.
Price date
Month and year of calculation, including VAT for private customers. A range without a date goes out of date unnoticed.
Next step
When and how the written cost estimate or quote arrives, and that only this document applies.
Cost of the estimate
Whether measuring up and the estimate cost anything. Without an agreement a cost estimate is, in case of doubt, not to be paid for (§ 632(3) BGB).
If a contract with a consumer is concluded solely by email, phone or website, the right of withdrawal also has to be considered; what applies there is explained in the article Cancellation rights for jobs booked by email and website. And a business that advises by video before the site visit likewise gives a range with assumptions there, not a cost estimate. How that works is described in the article on online consultation before the site visit.
What belongs in a cost estimate
The cost estimate itself is not produced on the website, but the website announces it, and like quotes it often goes out digitally: 68 percent (Bitkom, 2025 survey) of the trade businesses surveyed send quotes digitally. The document both sides will later refer to therefore often sits in the customer’s inbox, and it should be understandable on its own. It should contain:
- The label “cost estimate” and a sentence stating whether or not the business stands by the accuracy of the amount
- Items with quantities, units and unit prices, separated into labour, materials and travel
- The assumptions behind the calculation, for example about the condition of the substrate, pipes or masonry
- Work that is expressly not included
- A note that the business will report a likely substantial overrun without undue delay and agree the next steps with the customer
- Date, price date and, where applicable, a deadline until which the document applies
If the business warrants the accuracy of the estimate, § 649 BGB no longer applies, because the provision presupposes that exactly this warranty is missing (§ 649(1) BGB). The amount then becomes a commitment, and extra costs without a change of scope are usually borne by the business. A so-called binding cost estimate therefore comes close to a fixed price and should be described that way on the website too, so that the customer knows what kind of commitment they are getting.
For a quote with a fixed price, the binding effect of § 145 BGB applies. Setting a period within which the quote can be accepted limits that effect in time: acceptance is then only possible within the period (§ 148 BGB). Without such a period, a written quote can only be accepted for as long as the business may expect a reply under normal circumstances (§ 147(2) BGB). A date in the quote and a sentence about it on the website spare everyone the discussion about what normal circumstances are.
The duty to notify as a routine in the business
In practice, the notice under § 649(2) BGB rarely fails for lack of will, but for lack of a routine. The journeyman sees the deviation on site, the cost estimate is in the office, and the customer finds out with the invoice. For the notice to arrive in time, it needs a fixed route with clear responsibilities:
Report the deviation
Whoever spots extra work on site reports it to the office the same day, with a photo and a short description: what was found and which work is added.
Recalculate
The office recalculates the cost estimate with the new finding and compares the amount with the internal reporting threshold the business has set for itself.
Inform the customer
If a substantial overrun is likely, the notice goes to the customer without culpable delay, with the reason, the new amount and photos, preferably in text form so it can be proven later.
Record the decision
The customer decides whether work continues, the scope changes or the contract is terminated. Their answer is recorded in writing.
Invoice
If work continues, the invoice follows on the basis of the new calculation. If the customer terminates because of the overrun, the work done and the expenses are invoiced (§ 645(1) BGB).
Whoever spots extra work on site reports it to the office the same day, with a photo and a short description: what was found and which work is added.
The office recalculates the cost estimate with the new finding and compares the amount with the internal reporting threshold the business has set for itself.
If a substantial overrun is likely, the notice goes to the customer without culpable delay, with the reason, the new amount and photos, preferably in text form so it can be proven later.
The customer decides whether work continues, the scope changes or the contract is terminated. Their answer is recorded in writing.
If work continues, the invoice follows on the basis of the new calculation. If the customer terminates because of the overrun, the work done and the expenses are invoiced (§ 645(1) BGB).
Extra costs that the customer causes by wanting something different or more are a separate matter. That is not an overrun of the estimate but a change to the order. For construction contracts, meaning contracts for the construction, restoration, removal or conversion of a building, an outdoor facility or part of one (§ 650a(1) BGB), the law sets out its own procedure. The business is as a rule obliged to prepare a quote for the additional or reduced remuneration (§ 650b(1) BGB). If the two sides do not reach agreement within 30 days (§ 650b(2) BGB) of the change request being received, the customer may order the change in text form. The website does not need the details, but it does need one sentence: requested changes are priced before they are carried out.
One sentence on the website that prevents disputes
Where exactly this sentence goes depends on how the website is structured. If every service has its own page, it belongs where the range or the process for that service is described; why separate pages work better for this than one combined page is explained in the article Service pages instead of one combined page. How such sections are designed without the page turning into a price list is shown on the page Web design for trades.
Price-conscious customers, digital quotes
Two surveys show the setting in which this wording is read. For the Bitkom study report on digitalisation in the skilled trades, 504 (Bitkom, 2025 survey) trade businesses in Germany were interviewed by phone. 87 percent (Bitkom, 2025 survey) of the businesses surveyed observe that their customers have become much more price-sensitive. These customers read a figure on the website closely, and an invoice far above it just as closely.
On the other side is the search. In a representative survey of 1,004 people aged 16 and over (Bitkom Research, 2025 survey), about a quarter click through the websites of possible businesses when choosing a trade business (26 percent, Bitkom Research, 2025 survey). For 40 percent (Bitkom Research, 2025 survey), the lack of a website is even a reason to rule a business out. The website can thus be the first place where the customer sees an amount, and so the place where their expectation forms. What it says about guide price and cost estimate helps decide whether a later additional amount arrives as a surprise or as a possibility that was announced beforehand.
What putting this on the website costs
The changes are manageable: a note under the calculator result or the ranges in the pricing section, three sentences in the enquiry form, one sentence on the duty to notify on the service pages and a check of all texts for “§ 650”. The content is decided by the business: which assumptions it makes, whether measuring up and the estimate cost anything and from which deviation it reports internally. We build a website for trade businesses for a fixed price from 1,490 euros net, with up to eight pages, service pages, enquiry form and the legal basics. The copy is part of it, including the notes described in this article; they do not replace a legal review of the individual case. Ongoing maintenance costs from 49 euros net per month, cancellable monthly, with no minimum term; what it covers is set out under Maintenance and support. All prices, as of September 2026, are listed under Pricing.
A business that already has a website does not need a rebuild for this. The sentences can be added to existing pages; how the rest of the copy comes about is described in the article Website copy in the trades. The other services we offer are listed under Services, and what a new site costs overall is explained in the article What a trade website costs. For a question about your pricing section, you can reach us via Contact.
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