Sub-processors
Last updated: 2026-05-22
CelerSign engages a limited set of third-party sub-processors to operate the electronic signature service. Each sub-processor is bound by contractual obligations consistent with our Data Processing Addendum and applicable data protection laws.
We maintain this list publicly and will provide at least 30 days' notice before adding a new sub-processor that Processes customer Personal Data. To be notified of changes to this list, email legal@celersign.com with the subject line "Subprocessor updates" and we will add you to the notification list.
Current sub-processors
| Name | Service Provided | Data Categories Processed | Hosting Region |
|---|---|---|---|
| Vercel | Application hosting and edge compute | Request metadata, IP addresses, browser user-agent strings; ephemeral compute (no persistent data storage) | Global edge; primary US regions |
| Railway | Managed PostgreSQL database and Gotenberg container hosting | All application data: account information, document metadata, audit-trail records, signer details | US East (default) |
| Linode (Akamai) | S3-compatible object storage for documents and signed PDFs | Uploaded source documents, generated signed PDFs, signature image assets | US East (Newark, NJ) |
| ZeptoMail (Zoho Corporation) | Transactional email delivery | Recipient names and email addresses, email subject and body content (signing invitations, OTPs, completion notices) | United States / Zoho global infrastructure |
| Stripe | Payment processing for US and Canadian customers | Billing contact information, payment method tokens (no full card numbers stored by CelerSign), transaction metadata | United States |
| Gotenberg (self-hosted on Railway) | DOCX-to-PDF and HTML-to-PDF conversion | Document content during conversion (ephemeral; not persisted by Gotenberg) | US East (co-located with Railway database) |
| Google Drive (customer-owned) | Optional per-organization mirror of completed signed PDFs | Signed PDF copies, only into a customer-owned Drive folder, only when the customer opts in | Customer's Google Workspace region |
Regional payment processors
CelerSign also integrates with Paystack and Interswitch / Quickteller for African customers paying in local currencies. These processors are not used for North American customers and do not Process Personal Data of US or Canadian signers under normal operation.
Subscribe to updates
To receive advance notice of new sub-processors, email legal@celersign.com. A self-serve subscription form is on our roadmap.