The verdict in three sentences
For a B2B customer portal sending a few hundred contracts a month, an e-signature API integration pays for itself in under a year through cash-flow days gained. Yousign often offers the best value for a European SME, while DocuSign wins when customers are international or the group already uses it. The real question is not the tool but the eIDAS level: simple signatures cover most lease and credit agreements, qualified ones cost 4 times more.
The three eIDAS levels and their real cost
The EU eIDAS regulation defines three levels. The choice depends on contract value, dispute risk and your banking partners' requirements.
| eIDAS level | Signer verification | 2026 unit cost (mid volume) | Typical fintech use |
|---|---|---|---|
| Simple | Email + SMS code | EUR 0.50 to 0.90 | Order forms, amendments, delivery notes |
| Advanced | Verified ID document + SMS | EUR 1.00 to 1.50 | Lease agreements, guarantees |
| Qualified | Identity verified in person or by video + qualified certificate | EUR 2.00 to 4.00 | High-value contracts, regulated deeds |
| Electronic seal (company) | Issuer certificate | EUR 0.10 to 0.30 per document | Invoices, automated statements |
| Qualified timestamp | Timestamp token | EUR 0.05 to 0.15 | Proof of existence |
A simple signature is legally recognised across the EU (eIDAS Article 25), but in a dispute you must prove the reliability of the process. The advanced level partly shifts that burden, which is why it suits contracts above EUR 20,000 in cumulative payments.
Yousign, DocuSign or Dropbox Sign: 2026 comparison
| Criterion | Yousign API | DocuSign eSignature API | Dropbox Sign API |
|---|---|---|---|
| API entry price | From about EUR 150/month | From about $50/month (limited volume), quote above | From about $100/month |
| Unit cost at 300 signatures/month | EUR 0.50 to 1.20 | EUR 1.00 to 2.00 | EUR 0.80 to 1.50 |
| Data hosting | France (EU) | EU available, US headquarters | Mostly US |
| eIDAS qualified signature | Yes (qualified provider) | Yes, via partners | Not native |
| Documentation quality | Good | Very thorough | Good |
| Integration effort (existing portal) | 8 to 15 days | 12 to 20 days | 8 to 12 days |
Portal integration (EUR 6,000 to 14,000) covers generating the contract PDF from case data, sending through the API, status webhooks, archiving the audit trail and showing progress in the customer area.
Payback for 300 contracts a month
| Metric | Before (paper and emailed PDF) | After API integration |
|---|---|---|
| Average signing time | 9 days | 1 day |
| Mailing costs (tracked post, printing) | EUR 6 per contract, i.e. EUR 1,800/month | EUR 0 |
| Signature cost | EUR 0 | EUR 0.90 on average, i.e. EUR 270/month |
| Admin time per contract | 25 minutes | 5 minutes |
| Contracts abandoned before signing | 6% | 2% |
| Monthly chasing time | 50 hours | 10 hours |
The biggest gain is often invisible: starting payments 8 days earlier means 8 days of cash recovered on every file.
Mini case study
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
Sanne, CFO of an Amsterdam equipment-leasing fintech, signs 300 contracts a month with an average monthly payment of EUR 450. A Yousign integration with advanced signatures costs EUR 11,000, then EUR 1.20 per signature, i.e. EUR 360 a month. Monthly gains: EUR 1,800 of mailing removed, 100 admin hours saved at EUR 35 loaded cost (EUR 3,500), and 12 contracts saved from abandonment (4% of 300), i.e. EUR 5,400 of extra monthly payments. Excluding recovered payments, the net gain reaches EUR 4,940 a month: the integration pays back in 2.2 months.
FAQ
Is a simple e-signature valid for a lease agreement?
Yes, it is legally valid across the EU under eIDAS. For contracts above EUR 20,000 or with a personal guarantee, an advanced signature at EUR 1 to 1.50 strengthens the evidence.
How long does integration into an existing portal take?
Allow 3 to 6 weeks including testing and acceptance. The timeline depends mostly on automated PDF generation and status webhooks.
Should we keep signed contracts ourselves?
Yes, archiving the signed PDF and audit trail in your own system for at least 7 years (the Dutch retention period) is recommended. EU object storage costs under EUR 20 a month for 50,000 documents.
Can we switch e-signature provider later?
Yes, if the integration goes through an abstraction layer in your code. Switching then costs EUR 2,000 to 4,000 instead of a full rebuild.
Must customers create a Yousign or DocuSign account?
No, embedded signing happens in your portal or through a secure link. Customers only receive an SMS code, which pushes signing rates above 95%.
Let's scope your project. Tell us your contract volume, target eIDAS level and current portal: we will cost the integration between EUR 6,000 and 14,000 with a 3 to 6 week schedule. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
