Choosing an offshore accounting partner should feel safe, not risky. Yet the moment you share payroll, customer, or financial data with a third party, you inherit their security posture. This buyer’s guide breaks down what certifications actually mean, what your DPA must cover, how to evaluate sub-processors, and how breach response should work in practice.
What this section covers
- Plain-English definitions of SOC 2, ISO-27001, and GDPR so you can assess vendor claims
- A practical way to read reports and certificates without becoming an auditor
- The non-negotiables in your Data Processing Agreement (DPA) and transfer addenda
- How to assess sub-processors, incident response, and continuity plans
Start with scope: what data, which systems, where it flows
Before you ask for any certificate, map your own footprint:
- Data categories. Payroll, PII, financials, special categories (GDPR Art. 9).
- Systems. ERP, payroll, document portals, file transfer, BI, ticketing.
- Flows and storage. Where data is processed and backed up, including third countries.
This tells you what assurance you need: application-only, infrastructure, or both.
SOC 2 in practice (US-led assurance, used globally)
What it is. An attestation over controls relevant to security, availability, confidentiality, processing integrity, and privacy.
Type I vs Type II.
- Type I tests design at a point in time.
- Type II tests design and operating effectiveness over a period (usually 6–12 months). Prefer Type II for steady-state operations.
How to read it.
- Check the report period, scope, and sub-service carveouts.
- Review complementary user entity controls (CUECs)—these are things you must do for the controls to hold (e.g., enforce MFA for your users).
- Look for exceptions and vendor remediation plans.
- Ask for a bridge letter to cover the gap between the report end date and today.
What to request. Latest SOC 2 Type II report, bridge letter, and any independent pen test summary relevant to in-scope systems.
ISO/IEC 27001 (global ISMS standard)
What it is. Certification of a vendor’s Information Security Management System (ISMS) by an accredited body.
What to verify.
- The certificate scope includes the services and locations you will use.
- The Statement of Applicability (SoA) maps which Annex A controls are in scope.
- Evidence of internal audits and management reviews.
What to request. Current certificate, SoA, and a summary of recent surveillance audit findings and closures.
GDPR and UK GDPR: your DPA must match your processing reality
Roles. Identify controller vs processor for each data flow.
Core DPA terms to require.
- Purpose and categories of processing, retention, and deletion timelines.
- Security measures aligned to SOC 2/ISO controls.
- International transfers: Standard Contractual Clauses (SCCs) and/or UK IDTA, plus a Transfer Impact Assessment (TIA) naming third countries.
- Sub-processors: a published list, change-notification terms, and flow-down of equivalent obligations.
- Audit and remediation rights with reasonable notice.
- Breach notification timelines and cooperation duties.
What to request. Executed DPA, SCCs/IDTA with annexes, TIA, Record of Processing Activities (RoPA), and the vendor’s retention/deletion policy.
Sub-processors: transparency and flow-downs
Ask for a current sub-processor list with services, locations, and DPAs. Ensure contracts flow down your security and privacy requirements. Require advance notice and an objection mechanism for material changes.
Access control, encryption, and device posture
Minimum baselines for offshore accounting delivery:
- Least privilege with periodic access reviews and a joiner-mover-leaver process.
- MFA for all privileged and remote access.
- Encryption at rest and in transit; keys managed in KMS/HSM.
- Managed endpoints with disk encryption, EDR, and USB controls; MDM for BYOD.
Request policies and last completed reviews as evidence.
Monitoring, vulnerability, and testing
Expect:
- Central logging/SIEM with alerting and retention.
- Routine vulnerability scanning with patch SLAs (e.g., critical within a defined window).
- Annual independent penetration testing with tracked remediation.
Ask for scan summaries, patch metrics, and a pen test attestation.
Incident response and breach notification
A vendor should have:
- A written incident response (IR) plan with named roles.
- Tabletop exercises at least annually.
- A clear breach communication playbook and regulatory timelines.
Request the IR plan and last tabletop report. Confirm how you will be notified and how evidence is preserved.
Business continuity and disaster recovery
Review RTO/RPO targets, last BCP/DR tests, and data-center/region failover plans. Ensure backups follow the same security controls and meet your retention rules.
Quick evaluation rubric (use during shortlisting)
- Scope fit: Certifications and controls cover your services and locations.
- Evidence quality: Reports are current, specific, and include remediation.
- Privacy readiness: DPA, SCCs/IDTA, and TIA are complete and signed.
- Operational hygiene: Access reviews, patching, and incident drills are routine.
- Transparency: Sub-processor list is public and change-managed.
Summary
Security due diligence should be practical. If a vendor can show current SOC 2 Type II or ISO 27001 with a clear scope, deliver a complete DPA with transfer documents, name their sub-processors, and walk you through incident and continuity drills, you have a strong baseline. Use the questionnaire to keep every claim tied to evidence.
