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Security & PCI Compliance

Stay protected. Stay compliant.
And when something breaks, we fix it.

Paying.co keeps payment businesses secure and compliant — with proactive penetration testing, hardening, monitoring, and full PCI DSS audit management. And when an audit comes back with findings or a breach has already happened, our remediation team gets you back to compliant quickly. We partner with all major security firms and Qualified Security Assessors so the QSA you already trust stays in the loop, not out of it.

verified Works with all major QSAs · PCI DSS full lifecycle · Proprietary pen testing tools.
paying.co · security · pci-audit.log
// PCI DSS audit cycle — ongoing engagement
[scan]     external pen test · scope="prod"
[scan]     1,247 hosts · 0 critical · 3 medium

// Findings triaged & remediated
[remediate] SQL injection risk → "closed"
[remediate] TLS 1.0 endpoint → "closed"
[remediate] exposed env vars → "closed"

// QSA notified, retest passed, compliance maintained
[qsa]      retest scheduled · ref="AOC-2026-Q2"
[status]   PCI DSS 4.0 · "compliant"
verified_user
Current status
PCI DSS 4.0 · compliant · AOC-2026-Q2
check_circle All findings closed · QSA-confirmed
All
Major QSAs & Security Firms
PCI DSS
Full Lifecycle Management
100+
Person Engineering Team
24/7
Remediation Response
What We Do

Three ways we keep you secure and compliant.

Most security work shows up in one of three modes — you want to stay ahead of threats, you have an audit coming up, or something's already gone wrong and you need it closed out fast. Paying.co runs all three. One team, one phone number, full lifecycle — with all major Qualified Security Assessors and security firms in the loop.

♦ Pillar 01
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Proactive Security

Pen Testing · Hardening · Monitoring

Stay ahead of the threats that show up on audit reports. Comprehensive internal and external penetration testing using our own proprietary tools, security hardening across web, mobile, network, and cloud, plus continuous monitoring and vulnerability scanning so issues are caught before a QSA or an attacker finds them.

♦ Pen Testing ♦ Hardening ♦ Monitoring
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♦ Pillar 02
fact_check

Audit & Compliance

PCI DSS · QSA Coordination · Docs

End-to-end PCI DSS audit management — initial assessment, gap analysis, remediation planning, and final certification. We partner with all major Qualified Security Assessors and handle the coordination so the audit moves forward instead of stalling out. PCI documentation prepared or rebuilt from scratch if needed.

♦ PCI DSS 4.0 ♦ QSA Partners ♦ Documentation
Start an audit engagement arrow_forward
♦ Pillar 03
healing

Remediation

Audit Findings · Breach Response · Recert

When an audit comes back with findings, or a security incident has already happened, our engineers analyze what went wrong, build a strategic plan to fulfill the QSA's requirements, execute the fixes, and stay through retest and final compliance. We don't just patch — we close findings and document the close for the auditor.

♦ Findings Closure ♦ Breach Response ♦ Recertification
Get help with findings arrow_forward
How We Work

Comprehensive testing. QSA-aligned execution.

Whether we're hardening your environment before an audit or fixing findings from one that just landed, the approach is the same — combine automated tooling with manual verification, work alongside your chosen QSA, and document everything to a standard the auditor will accept on the first pass.

♦ 01
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Automated & manual testing

We combine automated scanning with hands-on manual verification — the kind of testing automated tools alone miss. Vulnerability assessment, application security review, code review, and compliance validation across the full scope of your environment.

♦ 02
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QSA & security firm partnerships

We collaborate with all major Qualified Security Assessors and security firms. The QSA you already trust stays involved — we work alongside them to close findings, prepare documentation, and keep the audit cycle moving forward without surprises.

♦ 03
description

Documentation that audits well

Pre-requisite PCI documentation built from scratch or rebuilt to match the current standard. Policies, procedures, network diagrams, scope documentation, and SAQ/AOC preparation — written the way QSAs actually want to receive it.

♦ 04
monitoring

Continuous monitoring

Compliance isn't a once-a-year project. Ongoing vulnerability scanning, threat detection, log monitoring, and quarterly reviews keep you compliant between audits — so the next audit starts from a clean position, not a scramble.

close Security as a fire drill
  • cancelFindings show up on audit day, nobody saw them coming
  • cancelScrambling for documentation that should already exist
  • cancelQSA waits while remediation drags on for weeks
  • cancelDifferent vendor for pen testing, audit prep, and remediation
  • cancelNext year, the same problems show up all over again
check Security as an ongoing partnership
  • check_circlePen tests, scans, and monitoring run continuously, not annually
  • check_circleDocumentation maintained and ready before the QSA asks
  • check_circleFindings closed and retested within the audit window
  • check_circleOne team across testing, audit support, and remediation
  • check_circleSame engineers who passed last year's audit are still on the project

Not just here when something goes wrong. Here to keep it from happening.

Most security vendors show up after the alarm goes off — after an audit returns findings, after a vulnerability gets disclosed, after an incident is already in the news. Paying.co does that work too, and we're good at it. Our engineers analyze previous PCI findings, build a strategic plan to close them, and stay through QSA retest. When things break, we fix them.

But the better version of this relationship starts earlier. Continuous pen testing using our proprietary tools. Quarterly security reviews. Documentation maintained between audits, not rebuilt under deadline. Hardening recommendations applied before they become findings. So when the next audit cycle starts, you're not scrambling — you're prepared.

We collaborate with all major security companies and Qualified Security Assessors. The QSA you already trust keeps their role; we handle the gap between their findings and your fixes. One team across pen testing, audit preparation, remediation, and ongoing compliance — with the same engineers from one cycle to the next.

Talk to our security team arrow_forward
Under the Hood

Proprietary tools. QSA-grade rigor.

Our security team builds its own testing tools alongside the commercial and open-source stack — for the tests that need to be tailored, repeatable, and faster than what off-the-shelf scanners deliver. Everything is documented, everything is reproducible, and everything is built to hold up under the scrutiny of a QSA review.

  • build_circle

    Proprietary pen testing tools

    Our team builds and maintains proprietary penetration testing tools alongside the commercial and open-source stack. Internal and external tests, web and mobile applications, network and cloud infrastructure — tailored to payment-specific threats that generic scanners miss.

  • person_search

    Automated + manual verification

    Automated scans catch the obvious; manual review catches the subtle. We pair scanning tools with senior engineers who walk the application, review the code, and probe for the edge-case vulnerabilities that automated tools were never trained to find.

  • handshake

    QSA collaboration model

    The QSA you trust stays the QSA. We collaborate with all major security companies and Qualified Security Assessors — preparing the evidence package, walking through findings, executing remediation, and standing ready for retest. We make the auditor's job easier, not harder.

  • monitoring

    Continuous compliance

    Compliance maintained between audits with continuous vulnerability scanning, threat detection, log monitoring, and quarterly reviews. The next audit starts from a known-good baseline, not from a months-long catch-up project.

audit-report.json · PCI DSS 4.0 engagement

  "engagement": "prod-pci-q2",
  "standard": "PCI DSS 4.0",
  "qsa": "partnered QSA · in the loop",

  "scope":
    "external": 1247,
    "internal": 312,
    "web_apps": 8
  ,

  "findings":
    "critical": 0,
    "high": 0,
    "medium": 3, // all closed, retested
    "low": 7
  ,

  "status": "compliant · AOC-2026-Q2"
QSA & Security Partnerships

We work with your QSA. Not around them.

Paying.co collaborates with all major Qualified Security Assessors and security firms in the payments space. The QSA you already trust stays at the center of the engagement — we handle the gap between their findings and your fixes, prepare the evidence package, walk the auditor through remediation, and stand ready for retest. The result: a cleaner audit cycle for you and a faster sign-off path for the QSA.

QSA aligned
handshake

All major QSAs

We've worked alongside the major Qualified Security Assessors that audit payment companies — the firms accredited by the PCI Security Standards Council. Whichever QSA you've engaged, we've likely worked with them before.

Security firms
shield

Security firm partnerships

We collaborate with major security and consulting firms across pen testing, incident response, and assessment engagements — complementing their work rather than competing with it. If they brought you the finding, we'll help you close it.

Standards
verified

PCI DSS 4.0 ready

Full PCI Data Security Standard 4.0 expertise — the current standard, the requirements that came with it, and the timelines for the future-dated requirements that are still rolling in. We map your scope, your gaps, and your path forward.

Coordination
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Audit coordination

One project manager handling the QSA relationship across initial assessment, gap analysis, remediation, evidence collection, and final certification. The QSA gets a clean evidence package; you get a predictable timeline.

Evidence
workspace_premium

Evidence & documentation

Policies, procedures, network diagrams, scope documentation, SAQ/AOC preparation, and the evidence trail that backs every control. Written the way QSAs want to receive it — not the way Wikipedia describes it.

Ongoing
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Multi-cycle support

The same engineers across consecutive audit cycles. Your QSA changes their requirements year over year, the standard evolves, and your environment grows. We stay through all of it, so each cycle starts ahead of where the last one ended.

What We Cover

The full spectrum of compliance and protection.

Our security expertise spans the eight domains that matter for payment-focused businesses. Whether the engagement is a single pen test or end-to-end PCI lifecycle management, every assessment, remediation, and ongoing review covers the same comprehensive scope.

lan

Network Security

Firewall configuration, network segmentation, traffic monitoring, and intrusion detection — the perimeter controls that PCI DSS scope evaluation depends on.

web

Web Application

OWASP Top 10 testing, XSS, SQL injection, broken authentication, API security — including the manual testing automated scanners always miss.

smartphone

Mobile Security

Mobile application penetration testing, static and dynamic code analysis, runtime protection, and secure storage review for iOS and Android apps.

cloud

Cloud Security

AWS, Azure, and GCP configuration review and compliance validation. IAM, S3/blob storage, network segmentation, and infrastructure-as-code hardening.

credit_card

PCI DSS

Full PCI Data Security Standard compliance — scope assessment, gap analysis, remediation, evidence package, and certification across DSS 4.0.

vpn_key

Access Controls

Authentication, authorization, role-based access, identity management, and privileged access review. The control category that finds the most audit issues.

policy

Policy & Governance

Security policies, procedures, compliance documentation, incident response plans, and the governance framework that ties operational controls back to written requirements.

monitoring

Continuous Monitoring

Ongoing vulnerability scanning, threat detection, log monitoring, and SIEM integration — the controls that keep you compliant between audits, not just during them.

How We Deliver

A real engagement. End to end.

Every Paying.co security engagement runs against a documented Statement of Work, with named owners on both sides and clearly defined milestones. Standalone pen tests typically land in 3–5 weeks. Full PCI DSS audit support runs the audit cycle — usually 3–6 months from kickoff to AOC. Remediation engagements scale to the scope of findings. Ongoing compliance support is structured as a continuous retainer with quarterly check-ins.

assignment
♦ Step 01

Initial assessment

We start with where you are — current PCI status, existing findings, last audit results, current QSA relationship, scope of your cardholder data environment. The assessment defines what's already strong, what needs work, and what the engagement should actually cover.

engineering
♦ Step 02

Gap analysis

We map your environment against PCI DSS 4.0 requirements (and any other relevant standards in scope), identify gaps, and prioritize them by audit risk and remediation effort. The output is a roadmap your team and your QSA can both agree on.

build
♦ Step 03

Remediation plan

Engineering plan for closing every gap — technical fixes, configuration changes, policy updates, training requirements, and documentation. Sequenced by dependency, scoped by realistic timeline, ready to execute.

task_alt
♦ Step 04

QSA coordination

We work alongside your Qualified Security Assessor throughout — sharing evidence, walking through remediation, answering follow-up questions, and standing ready for retest. The QSA gets a clean audit; you get a faster sign-off.

workspace_premium
♦ Step 05

Final certification

Through final retest, AOC issuance, and the close-out documentation. The audit cycle ends on a clear "compliant" status, with the evidence package archived for the next cycle and any standing findings tracked for follow-up.

support_agent
♦ Step 06

Ongoing support

The relationship doesn't end at the AOC. Continuous monitoring, quarterly reviews, incident response standby, and prep for next year's audit cycle. We stay between audits so the next cycle starts ahead, not behind.

Ready to Get Started?

Talk to our team.

Tell us what you're protecting and where things stand — an upcoming audit, fresh findings from one that just landed, a security incident in progress, or a proactive review of where you might be exposed. We'll come back with a plan, a timeline, and a fixed scope. You'll hear back from a security engineer, not a sales rep.

schedule
Response within one business day Most projects start with a 30-minute scoping call
engineering
You'll talk to an experienced sales engineer The person you brief is the person who scopes your build
handshake
No-obligation feasibility review We'll help you scope it and determine the best path forward that matches your budget and timeline
language
We speak your language English, Spanish, and Polish — fluent across our team and project leads
groups
Partners power our growth Much of our success comes from strong partnerships — if you're exploring one, we'd love to talk