CO Art. 3–5 · 375

Getting a quote signed off, digitally

A quote needs no signature to be valid — and binds you anyway, often for longer than you would expect. Knowing both changes how you negotiate. This page covers the binding periods, the difference from a cost estimate, and how to document approval so it holds up.

Short answers

Does a quote have to be signed?
No. Quotes are form-free (Art. 11 CO). The contract is concluded by acceptance — by email or a click. The signature serves proof, not validity.
How long am I bound by my own quote?
With a stated validity period: until it expires (Art. 3 CO). Without one, between absent parties: until a reply sent properly and promptly would have arrived (Art. 5 CO) — an indefinite period, but by no means an unlimited one.
How do I end the binding effect?
By limiting it from the outset: state a validity period, or expressly mark the quote as non-binding (Art. 7 CO).
Quote or cost estimate?
Two different things. A quote states a binding price. An approximate cost estimate does not — if it is exceeded disproportionately, the customer may withdraw from the contract (Art. 375 CO).
Which signature level is enough?
For a form-free quote, the simple electronic signature. What decides is not the level but what is documented alongside it: verified identity, timestamp, and an unchanged version.

A quote is an offer — and offers bind

In everyday use a quote is treated as a non-binding proposal to negotiate from. Legally it is not. It is an offer within the meaning of Art. 3 ff. CO, and an offer binds the party making it. If the other side accepts in time, the contract is concluded — with no further step, no countersignature, no order confirmation.

This is where businesses get caught out: a three-month-old quote is accepted, material prices have risen since, and the binding effect stands anyway. Not because anyone did anything wrong, but because nobody set a deadline.

How long the binding effect lasts

The Code of Obligations distinguishes three situations. The third is the uncomfortable one, because it names no fixed number.

The practical conclusion is simple: a validity period on the quote is not a formality, it is the instrument by which you limit your own exposure. "Valid until 30 September 2026" ends any argument about what a reasonable period would have been.

Quote or cost estimate — not the same thing

The two terms get used interchangeably, and the confusion is expensive. A quote states a price you are bound to. A cost estimate under Art. 375 CO is an approximate figure — and that is precisely where its risk lies: if the approximate figure is exceeded disproportionately, the customer may withdraw from the contract. For work on the customer’s own land, where withdrawal would be pointless, an appropriate reduction of the remuneration comes into play instead.

For businesses that estimate on site and invoice later, this is the decisive fork. Writing "cost estimate" on a document meant to be a binding quote gives away certainty. Writing "quote" when the work is not yet foreseeable binds you to a number you do not know.

What belongs on a quote

The law prescribes no content for validity — a contract can be concluded on a napkin. For traceability and VAT, a standard has nonetheless settled:

Document the approval, don’t just collect it

Because the quote is form-free, the signature is entirely about provability. And that turns on three questions rather than on the signature level: which version was accepted, who accepted it, and can it be shown the document is unchanged since?

The usual practice — PDF by email, reply "looks good, go ahead" — answers none of them reliably. The agreement refers to an attachment rather than an identifiable version. It sits in one person’s mailbox. And whether the PDF in your folder today is the one the customer opened is not demonstrable two years later.

For the large majority of jobs this never matters, because nobody disputes anything. It matters exactly when somebody does — and by then it is too late to create the documentation.

How long your quote binds you

Situation Binding effect Basis
Quote with a stated validity period Until the period expires Art. 3 CO
No period, between present parties (including by phone) Must be accepted immediately, otherwise it lapses Art. 4 CO
No period, between absent parties Until a reply sent properly and promptly would arrive Art. 5 CO
Expressly marked non-binding No binding effect — not an offer in the legal sense Art. 7 CO
Approximate cost estimate No price binding; right of withdrawal if exceeded disproportionately Art. 375 CO

How athemi handles the approval step

athemi is not quoting software and calculates nothing — the quote still originates where it originates today, often in your ERP. What athemi takes over is the step after: delivering it so that approval becomes a demonstrable fact rather than a line in a mailbox.

Try athemi free

Frequently asked

Is a quote without a validity period binding indefinitely?

No, but not briefly either. Between absent parties the offeror stays bound until a reply sent properly and promptly would arrive (Art. 5 CO). How long that is depends on the transaction and would be interpreted in a dispute — which is exactly why you set a period and remove the need for interpretation.

Is a verbal agreement on the phone enough?

For validity yes — a form-free contract can be concluded verbally. But note Art. 4 CO: between present parties, which includes a phone call, the offer must be accepted immediately or it lapses. And in a dispute it is one account against another.

What if the customer returns an amended quote?

That is not an acceptance but a new offer — and the roles reverse: now you are the one who may accept or decline. In practice this means every change deserves a new version with its own number, rather than being folded silently into the existing document.

Do we need an order confirmation once the quote is accepted?

Not legally — the contract already exists on acceptance. It is still useful in practice: it records which version governs and makes the moment of conclusion visible to both sides.

Related guides

Sources

This page summarises the legal position in general terms and is not legal advice. Whether a given document is a quote or a cost estimate is judged by its content and the circumstances, not by its heading.

Last reviewed: 2026-07-25