Is a signature made with a finger on a phone legally valid?

According to a legal opinion by the law firm Gałecki and Associates dated 21 August 2023, a signature made with a finger in SignSafe is a handwritten signature, and the declaration of intent meets the written form requirement (Art. 78 of the Polish Civil Code). If the signature failed the handwritten-signature test, the declaration is still valid in documentary form (Art. 77² CC). The handwritten signature is not a qualified one, but where the electronic form of Art. 78¹ CC is required, we can connect a qualified signature in SignSafe; a notarial deed is not possible. This summarises the opinion and is not legal advice.

According to a legal opinion by the law firm Gałecki and Associates dated 21 August 2023, a signature made with a finger in SignSafe is a handwritten signature and meets the written form requirement (Art. 78 of the Polish Civil Code). This summarises the opinion and is not legal advice. The examples refer to Polish law. SignSafe is a tool for document workflow and collecting signatures and does not compete with the qualified signature; a phone, internet and a finger take about a minute, with no excuse of “I cannot print and sign”. You can download the full document: legal opinion (PDF, in Polish).

Why is there doubt?

For years people signed with a pen on paper. When the same handwritten signature is made with a finger on a screen, some assume it “does not count”. Others assume any way of approving an electronic document is equally good. Both are simplifications. What matters is what form the specific act requires and the legal character of the signature itself.

What does the 2023 opinion say?

The opinion covers the “legal character of a signature made by hand on a touch screen”. Its main conclusions:

• a signature made in SignSafe is a handwritten signature (a biometric handwritten signature),
• a declaration of intent signed in the app meets the written form requirement (Art. 78 CC),
• if the signature failed the handwritten-signature test, the declaration is valid in documentary form (Art. 77² CC),
• it is not an “electronic signature” within the meaning of the eIDAS Regulation, so eIDAS standards do not apply to it,
• in effect it is equivalent to a qualified electronic signature: both preserve written form.

How is this different from an ordinary click or SMS code?

Clicking “I accept”, entering an SMS code or typing a name in a form is, as a rule, documentary form: a declaration made in a document showing who made it. A handwritten signature goes further, because it leads to written form, which the law requires for many contracts. In SignSafe, documentary form is therefore the fallback, not the main assumption.

Three forms worth separating

• Documentary form (Art. 77² CC): a declaration in a document from which it is clear who made it.
• Written form (Art. 78 CC): a declaration bearing a handwritten signature. According to the opinion, a signature made in SignSafe preserves it, as does a qualified electronic signature.
• Electronic form (Art. 78¹ CC) and notarial deed: the first requires a qualified electronic signature, the second a notary. SignSafe does not support notarial deeds, and where a qualified signature is required we can connect one.

When is a phone signature usually enough?

Examples where written or documentary form is sufficient (always depending on the specific matter):

• consents and statements with no special form prescribed,
• delivery confirmations, handover protocols, orders and quote acceptances,
• contracts for which the law requires written form,
• internal company documents and policies to be acknowledged.

When is a different way of signing needed?

• acts that require a notarial deed,
• acts that require the electronic form of Art. 78¹ CC or expressly a qualified signature,
• cases where an office, bank or the other party expressly requires a different way of signing (if it is a qualified signature, we can connect one in SignSafe).

In these cases a different way of signing works better, and SignSafe does not rule it out. A SignSafe handwritten signature is not a qualified electronic signature, and we do not claim it is; where a qualified signature is required, we can connect one in SignSafe. A notarial deed is not possible.

How can you show that the right person signed?

In a dispute the whole set of evidence matters, not only how the signature looks. It helps to have:

1. a PDF with the handwritten signature on it,
2. the signature summary page attached to the signed document: a unique SignSafe certificate identifier, date and time of sending and signing, the sender’s details and, for each signer, first and last name, e-mail, IP address, device (for example an iPhone), date and time and signing method,
3. the e-mail with the finished document that reaches the sender once everyone has signed,
4. the possibility of comparing the signature with the person’s other signatures by a handwriting expert.

According to the opinion of a forensic handwriting laboratory (Pracownia Grafologiczna) dated 29 August 2024, SignSafe signatures allow forensic comparative examination of handwriting. The court assesses the results freely, like any other evidence.

What to discuss with a lawyer

We do not settle questions that depend on a specific case. Discuss with a lawyer in particular:

• whether the law requires electronic or special form for your contract,
• how to word a clause on form in a framework agreement or terms,
• how the burden of proof works in your industry (employment, medical, real estate documents),
• whether high-value documents should have a stricter form.

Is a phone different from a tablet or computer?

As to the legal character of the signature, there is no basic difference: in each case it is a handwritten signature recorded on a digital document. Convenience differs. A phone or tablet lets you sign with a finger as on paper, while on a computer you sign with a mouse or trackpad, which usually reproduces handwriting less faithfully. The expert recommends full-form, legible signatures with first name and surname.

What next

• Read the full overview on the Legal security page.
• See how a handwritten signature online works.
• Check how to sign a document in a few steps.
• Questions about your case? Contact us.