April 2026 · Developer Guide
White-Label E-Signature API: Embed Signing in Your App Under Your Brand
Your users shouldn't know you're using a third-party signing service. Here's how to embed legally binding e-signatures in your SaaS product — no third-party branding, no iframe, no SDK.
Founder, Signbee
What "white-label" means for e-signatures
White-label means your end users never see the signing provider's name. Emails come from your domain. The signing page shows your branding. The signed PDF credits your product, not the third-party API.
There are three approaches to white-label signing, in order of integration depth:
1. API-first (deepest integration)
You call the API from your backend. Your app controls the entire UX — document preview, signature capture, and confirmation. The API only handles PDF generation, storage, and SHA-256 certificate creation. No third-party UI is exposed to your users.
2. Embedded iframe (partial white-label)
You embed the signing experience in an iframe within your app. The signing page is hosted by the provider but styled with your logo and colours. Common with Dropbox Sign and SignWell.
3. Self-hosted (full control)
You host the entire signing infrastructure yourself. DocuSeal is the main option here — open-source, self-hostable, with full control over branding and data.
Approach 1: API-first white-labelling with Signbee
With an API-first approach, your backend calls the signing API directly. Your frontend handles the entire user experience. The signing provider is invisible.
// Your SaaS backend — e.g., when a user creates a proposal
const response = await fetch('https://signb.ee/api/send', {
method: 'POST',
headers: {
'Authorization': `Bearer ${process.env.SIGNBEE_API_KEY}`,
'Content-Type': 'application/json',
},
body: JSON.stringify({
content: proposalMarkdown,
senderName: 'Acme Proposals', // Your product name
senderEmail: 'contracts@acme.com', // Your domain
recipientName: clientName,
recipientEmail: clientEmail,
}),
});
const { id } = await response.json();
// Save document ID to your database for trackingYour user sees: "Acme Proposals sent you a document to sign." No mention of Signbee. The signing link goes to signb.ee for the signing ceremony, but the document header shows your sender name and email.
Comparison: white-label e-signature APIs
| Provider | Approach | Custom branding | Starting price |
|---|---|---|---|
| Signbee | API-first | Sender name/email customisable | Free (5 docs/mo) |
| Dropbox Sign | Embedded iframe | Logo + colours | $49/month |
| SignWell | Embedded + API | Branding on paid plans | 25 free docs/mo |
| DocuSeal | Self-hosted | Full control | Free (open-source) |
| DocuSign | Embedded + API | Enterprise plans only | Custom pricing |
Use cases for white-label signing
Proposal software — Your users create proposals and send them for signature. The client sees your product name, not a third-party signing tool.
HR platforms — Offer letters, NDAs, and employment contracts sent under your HR product's branding.
CRM / sales tools — Contracts flow from deals to signatures without breaking the CRM experience.
Property management — Lease agreements signed under the property management company's brand.
Legal tech — Client engagement letters and retainers sent directly from the law firm's own platform.
Marketplace platforms — Freelancer contracts and service agreements issued under the marketplace brand.
What to look for in a white-label signing API
- Custom sender identity — Can you set the sender name and email to your product's brand? This is the minimum viable white-label.
- No provider watermark — Does the signed PDF contain the provider's logo or only your branding?
- Custom email domain — Can signing invitation emails come from your domain (e.g., contracts@yourapp.com)?
- API-first design — Can you build your own UI around the signing flow, or are you forced into an iframe?
- Pricing at scale — Per-document pricing can become expensive when signing is a core product feature, not an add-on.
- Audit trail — Does the signing certificate include sufficient evidence for legal compliance?
FAQs
What is a white-label e-signature API?
An API that lets you embed document signing in your product without exposing the third-party provider's brand. Your users see your branding throughout the signing experience.
Which providers support white-labelling?
Signbee (API-first), Dropbox Sign (embedded iframe), SignWell (embedded + API), DocuSeal (self-hosted), and DocuSign (enterprise only). Each offers different levels of customisation.
Is a white-label signature still legally binding?
Yes. The legal validity of an electronic signature comes from the signing process and audit trail, not from whose brand appears on the document. White-label signatures are fully valid under ESIGN, eIDAS, and ECA.
Related resources
Embed signing in your product — free tier, no credit card.