Quote vs. Cost Estimate: The Difference

The table also shows why the label alone provides little certainty. A document titled “Quote” may contain wording such as “subject to change” or variable quantities. Conversely, a binding cap can be agreed for a cost estimate; if the business expressly guarantees the accuracy of the estimate, the special rule of § 649 BGB does not apply. Content, price logic and acceptance process must fit together.

What a quote specifically fixes

A quote describes which service is to be provided under which terms. For a clear order, it should in particular include line items, quantities or billing units, unit prices, total amount, time specifications, and any exclusions.

Whoever submits a quote is bound by it unless they have excluded that binding effect (§ 145 BGB). If it is accepted without changes and in time, the terms stated therein are generally part of the contract. If the customer adds new wishes in their reply, however, there is no unchanged acceptance: an acceptance with extensions, restrictions or other changes counts as a rejection combined with a new offer (§ 150 para. 2 BGB). The business then decides on this new offer.

The binding effect does not apply indefinitely. If the quote states an acceptance period, the customer can only accept within that period (§ 148 BGB). If no period is stated, a quote sent by post or email can only be accepted for as long as the business may, under normal circumstances, expect a reply (§ 147 para. 2 BGB). A late acceptance counts as a new offer (§ 150 para. 1 BGB). A dated “valid until” therefore creates clarity for both sides.

A quoted total amount is also not automatically a flat price. If the document contains estimated quantities and fixed unit prices, the final invoice may deviate from the stated sum if different quantities are actually billed. That is why it should be stated directly next to each quantity whether it is fixed, estimated, or to be billed based on measurement.

What a cost estimate states

A cost estimate is a professional pre-calculation of the anticipated costs. It is based on the discernible scope of work, the assumed quantities, and the labour, material and incidental costs known at the time of calculation.

The document therefore answers a different question than a fixed-price quote: “What effort is to be expected based on the current assessment?” For repairs, fault-finding, and work on concealed components, this form can be sensible because part of the actual scope only becomes visible during execution.

So that “anticipated” does not become too arbitrary, the cost estimate should state its assumptions. Examples include “calculation without disassembly”, “line behind the panelling not checked” or “material quantity estimated based on visible area”. The customer can then recognise which finding might trigger a new calculation.

For practical control, a calculation method is needed first. The percentage deviation is calculated as follows:

(new amount − cost estimate) ÷ cost estimate × 100

Example: A cost estimate states 4,800 euros. During the work, additional services worth 720 euros, which were not previously recognisable, are calculated. The new amount is 5,520 euros; the calculated deviation is 15 percent.

(5,520 € − 4,800 €) ÷ 4,800 € × 100 = 15 %

These 15 percent are only the result of the example and not a legal limit. § 649 BGB merely refers to a “significant overrun” and does not name a percentage. Whether an overrun is significant depends, according to the IHK Köln, on the circumstances of the individual case, such as the type and scope of the service, the point in time at which the additional costs became apparent, and how precisely the estimate was worded. What is decisive is the total estimated sum, not the individual item; additional costs from extra services requested by the customer themselves do not count towards this.

As guidance for what is still an insignificant overrun, the commentary literature on the BGB cites deviations of 10 to 20 percent, and in particular exceptional cases up to 25 percent; this is how the IHK Köln and the Handwerkskammer Rheinhessen summarise it. These are guide values from legal literature, not statutory thresholds. A blanket percentage should therefore not be stored as an automatic approval limit in templates or software.

An internal warning system does not replace a legal limit

For operational workflow, a self-defined warning threshold can nevertheless be useful. It merely controls when an order is reviewed again internally and discussed with the customer. It does not decide what is legally still insignificant.

A possible three-tier model:

• Up to 5 percent expected deviation: Check the calculation and document the cause.
• Above 5 up to 10 percent: Pause the order, if practically possible, and prepare an updated calculation.
• Above 10 percent: Obtain new approval with the changed scope, new amount, and new version number.

The thresholds are an operational decision aid. A team can set them lower if small budget deviations are particularly relevant for its customers. For the legal assessment of a specific overrun, the individual case remains decisive. Regardless of any internal threshold, the statutory duty to notify applies as soon as a significant overrun is to be expected (§ 649 para. 2 BGB).

Checking additional costs by cause rather than by percentage alone

A deviation becomes more understandable when it is attributed to a cause. The change notification should contain at least four figures:

1. Amount previously calculated,
2. Newly added or changed item,
3. Expected new total amount,
4. Absolute and percentage difference.

In addition, the cause should be stated: additional customer requests, deviating actual quantities, damage only visible after opening up, or an incorrect initial assumption. This attribution separates a genuine change in service from a mere calculation error.

If a significant overrun is to be expected, the contractor must notify the customer without delay (§ 649 para. 2 BGB). If the customer terminates the contract as a result, the business is only entitled to the claim specified in § 645 para. 1 BGB: a portion of the remuneration corresponding to the work performed and reimbursement of expenses not included therein. If the customer does not terminate the contract, the business can, according to the IHK Köln, claim the remuneration actually incurred. If the business culpably fails to give notice, claims for damages may arise: the customer must then be put in the position they would have been in had they been informed in time. For a specific dispute, the contractual situation should be reviewed individually.

Three questions lead to the right form

1. Is the scope of services fully verifiable? If quantities, materials and execution are already established, a quote usually fits better. If concealed damage, diagnostic work or open quantities are to be expected, a cost estimate more transparently represents the uncertainty.

2. Does the customer expect a fixed budget framework? Then it should be expressly clarified whether a fixed price, a price cap, unit prices, or merely an estimate is meant. A fixed budget must not only be mentioned in a phone call while the document uses a different price logic.

3. Can a deviation be coordinated before it arises? If so, the process needs a clear checkpoint: pause the work, describe the change, state the new total amount, and document the approval. If a pause would be technically problematic, this case should be discussed before the order begins.

Making execution conditions visible in October and November

For roofing, garden, façade, heating or vehicle work, weather, limited daylight hours and seasonally dependent scheduling windows can affect execution in October and November. The document should therefore distinguish between price commitment and the execution period.

Instead of “execution in autumn”, concrete details are more helpful: the planned calendar week, the required lead time, prerequisites for outdoor work, and how weather-related postponements are handled. If an order must be completed before frost, winter storage, or a planned use, this customer goal belongs in the enquiry and in the scheduling discussion.

For an expiring quote, the business should check before a later acceptance whether capacity, quantities and calculation bases are still valid. Acceptance after the deadline counts as a new offer (§ 150 para. 1 BGB), which the business is not obliged to accept. A new version with a date makes the valid basis recognisable without asserting an unsupported seasonal surcharge or a blanket price development.

Agreeing a fee before creation

In case of doubt, a cost estimate is not to be remunerated (§ 632 para. 3 BGB). However, remuneration can be expressly agreed. A clause in general terms and conditions that makes cost estimates generally chargeable was held invalid by the OLG Köln (decision of 27 June 2011, 19 U 45/11); according to the IHK Köln, however, this question is not undisputed. Anyone wishing to charge a processing fee should therefore separately agree the amount, scope and possible offsetting against a later order with the customer before creating the document, and record this agreement in writing or in text form for evidentiary purposes.

A clear agreement can, for example, state whether inspection, diagnosis, measurement or disassembly are included. The question of what is charged in the absence of a commissioned order also belongs before the service is provided, not as a surprise on the later invoice.

Quote or cost estimate for the insurer?

In the event of an insurance claim, the customer should first ask which document the respective insurer requires for assessment. The terms are not used consistently in everyday practice, and the required evidence can depend on the claim and the contract.

Six points should be clarified before creation:

• Desired document type,
• Claim or case number,
• Required photos and findings,
• Disclosure of net, tax and gross amounts,
• Desired breakdown by labour, material and incidental services,
• Required approval before commissioning.

Whether a fee for the cost estimate will be reimbursed should also be clarified directly with the insurer. The business should not give any reimbursement commitment on behalf of a third party.

An expert report serves a different purpose in the workflow than a cost calculation: it examines and assesses a matter of fact, whereas a quote or cost estimate describes the planned services and prices. If the insurer expressly requires an expert report, this requirement cannot therefore be replaced simply by a more detailed price list.

For quality control, every document can be assessed against twelve criteria. 0 points are awarded per criterion for “missing”, 1 point for “partially clear”, and 2 points for “clear”. A maximum of 24 points can be achieved.

Twelve criteria for a verifiable document

1. Document type is clearly labelled.
2. Scope of services is concretely described.
3. Excluded work is stated.
4. Quantities and units are comprehensible.
5. Unit or item prices are assigned.
6. Net, tax and total amount are clearly separated.
7. Labour, material, travel and incidental services are comprehensibly itemised.
8. Price logic and any variable components are explained.
9. Execution period and prerequisites are stated.
10. Validity or decision period is dated.
11. Date, document number and version are present.
12. Acceptance, query or change approval has a clear path.

The evaluation is deliberately simple:

• 20 to 24 points: Ready to send, unless a technical query is still open.
• 14 to 19 points: Clarify open items before sending.
• 0 to 13 points: Revise the document and review the scope of services again.

On criterion 6: anyone offering services to consumers must state the total price including value-added tax and highlight it in the event of an itemised breakdown (§ 3 PAngV).

The check assesses readability and process quality. It is not a legal review. Anyone starting on the structure will find a suitable document structure in the internal guide Writing a quote: structure and template.

A quote or cost estimate should still make it possible to recognise later which version was commissioned. A workflow with seven stages is suitable for this:

1. Record the enquiry: Note the customer's request, appointment, location and budget requirement separately.
2. Choose the document type: Check uncertainties, quantities and the desired price effect.
3. Calculate: Document items, assumptions and exclusions.
4. Send the version: Record document number, date and version status.
5. Assign the commissioned order: Link acceptance or order to the version sent.
6. Log changes: Record cause, additional or reduced costs, and approval.
7. Derive the invoice: Only carry over commissioned items and documented changes.

Software should not overwrite the original version with later changes. Version 1, customer approval, revision status and invoice together form the process history. How this transition can be mapped technically is shown in the article Automatically converting quotes into invoices.

Four typical mistakes and their early warning signal

Mixed price terminology: The title says “Quote”, but the text switches between “fixed price”, “estimate” and “approx.”. The warning signal is that no one can explain in a single sentence which amount is fixed and which is variable.

Unclear lump-sum items: “Material and installation: 3,500 euros” does not show what changes if the quantity changes. An early sign is the customer's first question about unit count, area, or hourly rate.

Changes only by phone: The invoice later contains an item that does not appear in any document version. A short confirmation with the new total status should therefore follow every change discussion.

Overwritten calculation: When updating, the originally accepted version disappears. Continuous labelling such as ANG-104-V1, ANG-104-V2 and RE-104 keeps the relationship between the documents visible. For ongoing filing, the workflow Managing quotes and invoices helps.

What is binding, a cost estimate or a quote?

A quote accepted without changes and in time generally binds the parties to the services and prices agreed therein (§ 145 BGB). A cost estimate, on the other hand, regularly calculates anticipated costs. It becomes binding if the business expressly guarantees a price cap or assumes liability for the accuracy of the estimate (§ 649 para. 1 BGB). What matters is the wording and the scope of services, as explained by the IHK Köln.

When a cost estimate and when a quote?

A quote fits when the service, quantities and execution are sufficiently established. A cost estimate is suitable when the effort only becomes more precisely recognisable through diagnosis, opening up, or measurement. For open quantities, a quote with unit prices and clearly marked estimated quantities can also make sense.

How large may the difference between quote and invoice be?

For a quote, the answer depends on the agreed price form, the actual scope of services, and documented changes. For a cost estimate, § 649 BGB does not specify a percentage limit; whether an overrun is significant is assessed on a case-by-case basis. The commentary literature cites 10 to 20 percent as guidance for a still insignificant overrun, and in exceptional cases up to 25 percent – a guide value, not a statutory limit (Handwerkskammer Rheinhessen). If a significant overrun is to be expected, the business must inform the customer without delay. Businesses should therefore quantify, justify and coordinate expected additional costs early.

What is the difference between a cost estimate and a quote for tradespeople?

In the trades too, the core difference lies in the price effect and purpose: the quote proposes concrete contract terms, the cost estimate calculates the expected costs of a job. The Handwerkskammer Rheinhessen expressly distinguishes the cost estimate from the legally binding quote. For repairs, it should additionally be documented which components were checked and which assumptions remain open.