ProofWorks Limited
Sub-processors
Last updated: 4 May 2026
To deliver the BidEngine platform, ProofWorks Limited engages a small number of carefully-selected third-party services (“sub-processors”). This page sets out the categories we use, their data locations, and the safeguards in place.
The detailed list of named sub-processors, with the specific vendor in each category and a copy of our Data Processing Agreement, is available to customers and qualified prospects on request, email privacy@bidengine.co.
Categories of sub-processor
| Category | Purpose | Data location | Transfer mechanism |
|---|---|---|---|
| Primary database | Stores customer evidence library, tender data, account records, and audit logs | UK only | UK only, no transfer |
| Application hosting | Hosts the platform and runs serverless functions; primary processing in the UK | Primary region: London (LHR) | UK IDTA where the parent vendor is non-UK |
| Large language models | Generation, scoring, and improvement of tender responses; embedding for semantic search | United States | UK IDTA. Customer data is not used for model training under our agreements. |
| Authentication | User sign-up, sign-in, session management, multi-factor authentication | United States | UK IDTA |
| Payment processing | Subscription billing | UK contracting entity, with limited US processing under the UK’s adequacy framework | UK IDTA where applicable |
What our sub-processors see, and don’t see
- Per-tenant isolation: each customer’s evidence library is logically isolated and is never used in another customer’s drafts.
- AI providers see only the specific content needed for an inference call, the question being answered and the relevant evidence records selected by our retrieval layer for that question. They do not see your full evidence library.
- Authentication and payment providers see identity and billing data only. They do not see your evidence library or tender data.
- No advertising networks and no third-party marketing trackers operate on the application.
Sub-processor changes
If we add a new sub-processor that processes personal data, we will notify active customers by email at least 30 days in advance. Customers may object to a new sub-processor on reasonable data protection grounds during the notice period; if we cannot accommodate the objection, the customer may terminate the affected service.
How to obtain the detailed list
The named sub-processor list is a commercially-sensitive document that we share with customers and with qualified prospects in active evaluation. To request a copy, email privacy@bidengine.co from a corporate domain. We will share the list together with our Data Processing Agreement, typically within one working day.
Public sector procurement teams: we are familiar with standard ITT data protection schedules and will respond to formal data protection questionnaires (e.g. CCN, GCloud, supplier security assessments) on the same email address.