Service · Software development

Custom CSRD reporting software development.

Custom software for the Corporate Sustainability Reporting Directive: data point management, ESRS coding, scope 1–3 calculations and XBRL export to ESEF. For corporations and consultancies that find a standard CSRD platform no longer sufficient or that need to account for a sector-specific data set.

ESRS codingScope 1–3XBRL/ESEFAudit trail

CSRD is not a report, it is a data stream.

From the 2024–2026 financial years, the Corporate Sustainability Reporting Directive requires large companies to report under the ESRS standards on climate (E1), environment (E2–5), social topics (S1–4) and governance (G1). In practice, that means well over a thousand data points per organisation, each with an owner, a source, a calculation rule and an audit trail. That is not an annual reporting exercise; it is a continuous data process that carries the same weight as your financial administration.

We build custom software for groups that hit the limits of a standard SaaS platform. Not a full replacement of Position Green, Workiva, Watershed, Plan A or EcoVadis for a corporate that is perfectly happy with them, but the layer around them, the integration layer or the sector-specific module that covers your situation and where the SaaS roadmap has stalled.

Our clients are industrial groups, real estate and infrastructure companies, food producers, retail groups, listed companies and sustainability consultants who serve multiple clients on one platform. What we keep seeing: the standard CSRD tools cover the generic ESRS data points broadly, but leave gaps where your sector or structure differs, such as scope 3 categories unique to your supply chain, an ERP integration that does not exist, or a multi-entity consolidation too complex for the standard flow.

Two obligations that draw on the same data: the WPM report on work-related mobility and, when importing steel, aluminium or cement, the CBAM declaration on embedded emissions.

Three types of CSRD software we build.

What we deliver depends on your reporting obligations, your IT landscape and the extent to which you need to consolidate by sector or across multiple entities. If you are also subject to a producer responsibility scheme, such as UPV textiles, that applies to specific product streams with fixed percentages and has nothing to do with your annual report. In the first conversation, we will advise which approach fits.

Compact project · fixed sprint budget

Integration layer on top of your existing CSRD platform

You use Workiva, Position Green or Watershed but have to enter data manually from your ERP, MES or HRIS. We build the ETL layer that retrieves the data automatically, validates it, converts it to ESRS format and passes it on — with data ownership, error notifications and an audit trail your assurance auditor can follow.

ETLData validationESRS mappingAudit trail
Mid-sized project · fixed sprint budget

Sector- or group-specific CSRD platform

For manufacturing with a complex scope 3 chain, real estate with a CRREM pathway, food supply chains or multi-site groups with different data sources per location. Your own data model, your own calculation rules, your own consolidation logic — integrated with your ERP and accounting system, but without the generic limitations of an off-the-shelf package.

Scope 3ConsolidationSector metricsERP integration
Larger project · fixed sprint budget

White-label CSRD platform for consultancies or franchises

For sustainability consultants, accountancy firms or franchise organisations that want to support multiple clients on a single platform. Multi-tenant architecture, tenant-specific materiality analysis, a branded portal per client and an assurance portal in which the external auditor can review reports and data points per client.

Reporting is not the same as acting. For the due diligence side, where you identify and follow up on risks at direct business partners, see CSDDD software.

Multi-tenantWhite-labelAssurance portalXBRL/ESEF

What your organisation gets at the end.

A production-ready CSRD application plus everything your sustainability team, IT department and external auditor need to run and defend the reporting cycle themselves.

  • Production and acceptance environmentsTwo separate environments in your cloud (GCP/AWS/Azure) or with us, with isolated test data so production figures are never contaminated by experiments.
  • Full codebase and architecture documentationSource code, build instructions, data model and infrastructure overview. Your IT team or another party can take it over whenever you choose.
  • ESRS data model and calculation rulesA configured set of data points mapped to ESRS E1–E5, S1–S4 and G1, with scope 1–3 formulas, an emission factor library and version history so a figure can always be traced back to the rule that applied at the time of reporting.
  • Integrations with your source systemsIntegrations with your ERP (SAP, Microsoft Dynamics, Exact, AFAS, Oracle), MES, HRIS, energy suppliers and logistics partners — automatic, validated and with error notifications when a value is missing or falls outside the expected range.
  • Audit trail and assurance portalEvery change logged, every approval recorded, every source connection traceable. A separate review environment in which your external auditor can assess the figures without access to production systems.
  • XBRL export for ESEFInline XBRL tagging in line with the ESRS taxonomy, with output ready for ESEF filing. Validation checks before submission so unexpected tagging errors are not a risk.
  • Training and handoverWorkshops for your sustainability team, data point owners and IT, plus a short guide for local data suppliers at sites that take part in the consolidation with you.
  • Ongoing maintenance (optional)Security patches, monitoring, backups, and further development in response to new ESRS guidelines or EFRAG updates. Fixed monthly price, with four response-time levels depending on your audit cycle.

When custom is the right choice.

Standard CSRD platforms such as Position Green, Workiva, Watershed, Plan A, ESG Book, Sphera and EcoVadis cover the basics well for most large companies. We only recommend custom software when you recognise one of these patterns. Otherwise, you're better off with a SaaS licence and a good implementation partner.

Sector-specific

Industry, real estate or food chain

Your scope 3 chain has categories that don't exist in an off-the-shelf package — a manufacturer with complex upstream data, a property portfolio steered along a CRREM pathway, or a food chain with agricultural emission factors per supplier. The calculations are unique, and so is the data model.

Integration-heavy

Automatic feed from ERP, MES and HRIS

Entering data points by hand in a SaaS portal doesn't scale when you have hundreds of measurement points per quarter. You want energy, production and workforce data to flow automatically from SAP, Dynamics, Exact, AFAS or an MES — validated, with error alerts and without shadow spreadsheets.

Multi-entity

Group with different sources per site

Your sites run different ERPs, have different measurement infrastructure and supply data in different units. A standard package requires everything to be delivered uniformly; custom software leaves the complexity at each site and consolidates it at group level without local teams carrying the burden.

White-label

Consultancy with multiple clients

You advise dozens of clients on their CSRD journey and don't want to put each of them on a separate SaaS licence. One multi-tenant platform with your branding, your methodology and your materiality assessment — and an audit portal where you and the external auditor can work per client.

Not sure about a large project yet?

Test your idea first: a working prototype in 1 day

With OneDayBuild, we make your idea tangible in a single day for €1,150, so you know whether further development is worth the investment. Decide to go ahead with the full build? Then we deduct the cost in full.

View OneDayBuild →

Modules we typically build or integrate.

A CSRD application is rarely a single screen with a single purpose. Under the hood sits a set of modules that feed each other. Which ones you need depends on your reporting context and existing tooling — not every module is relevant for everyone. Below are the building blocks we most often deliver or connect to an existing platform.

Data model

Data point management with ESRS coding

A register of all ESRS data points with an owner per point, source system, frequency and retention period. Every change is logged, with version history so a figure can always be traced back to who changed what and when — the basis for any assurance discussion with your external auditor.

ETL

Integration and validation layer

Automatic data feeds from ERP, MES, HRIS, energy suppliers and logistics. Validation on unit, range and completeness, with error alerts routed to the right data owner. See also our page on smart API integrations for the broader integration approach.

Calculations

Scope 1, 2 and 3 with an emission factor library

A configurable calculation engine for scope 1 (direct emissions), scope 2 (purchased energy, market- and location-based) and scope 3 (fifteen categories, covering the whole chain). Emission factors from DEFRA, IEA, sector databases or your own supplier-specific data. Version history per factor.

Workflow

Input, review and approval flow

Data point owners submit figures, a reviewer checks them, a manager approves and the controller signs off. Status updates per data point, escalations when things are delayed, and a dashboard showing for each reporting period which points are still open and who needs to act.

Assurance

External auditor portal

A separate review environment for the external auditor — access to figures, audit trail, underlying source documents and the calculation rules that applied at the time of reporting. Ask questions, leave comments and record approvals without access to your production systems.

Report

Report generation and XBRL export

Automatic report generation in the ESRS format, with inline XBRL tagging in line with the ESRS taxonomy. Output ready for ESEF filing with the Dutch AFM, plus a published HTML version for your stakeholders. Validation checks before submission.

Materiality

Double materiality assessment

Tooling for the double materiality assessment — impact materiality (your effect on people and the environment) and financial materiality (sustainability risks to your business operations). Stakeholder research, scoring per topic, thresholds and a substantiated materiality report for the annual accounts.

Trend

Year-on-year tracking and gap analysis

Year-on-year comparisons, progress against reduction targets, and gap analysis against sector benchmarks and internal targets. Visual reports for the board, the sustainability team and external stakeholders, fed by the same auditable data as the official CSRD report. See also our page on a custom KPI dashboard.

Consolidation

Multi-entity and multi-site

Aggregation of data from multiple sites, subsidiaries or joint ventures with different ERPs and metering infrastructures. Elimination rules for intra-group transactions, unit and currency conversions, and an auditable consolidation trail from site to group.

Governance

GDPR, data governance and access management

Role-based access per data point category, GDPR-compliant handling of staff and supplier data in ESRS S1–S4, encryption in transit and at rest, and a DPIA for every larger project. Access and exports are logged, and retention periods are applied automatically to archived data.

How a CSRD software project works.

1

Introduction and scope

A conversation to understand whether you fall under CSRD and from which reporting period, which SaaS platform you may already be using, what your IT landscape looks like and which ESRS topics are material. We also discuss which standard packages you currently use and what we would integrate with rather than replace.

2

Discovery with the sustainability and IT teams

Workshops with your sustainability coordinator, controllers, IT and, depending on your materiality, HR and facilities. We map out the ESRS data point register, map source systems, identify data owners and determine which modules are in scope. At the end you have a validated scope, a first screen flow and a calculation rules document.

3

Building in sprints with demonstrable progress

Every two weeks, a working build that your team and your external auditor can test. We integrate with your source systems early so that integration risks don't blow up at the end. A first module, such as energy and scope 2, is up and running after a few sprints, while a full multi-entity consolidation takes several sprints.

4

Audit dry run, pen test and rollout

Pen test, DPIA and an audit dry run with your external auditor on real data. Phased rollout: first one entity or one ESRS cluster, then scaling up. After that, ongoing maintenance with security patches, monitoring and further development whenever EFRAG or the European Commission tightens the standards.

Frequently asked questions about CSRD software.

What sustainability coordinators, controllers and IT managers usually want to know before we start.

Do you replace Workiva, Position Green or Watershed?
For a complete CSRD reporting chain at a large corporate, a standard SaaS platform is usually the right choice: these are mature, up to date with the ESRS and cover the generic data points well. We step in when you hit the limits: sector-specific metrics, an ERP integration your SaaS vendor doesn't build, multi-entity consolidation that becomes too complex, or a white-label setup for consultancies. In some cases we replace the SaaS entirely, typically when no package covers the combination, but in most projects we build the smart layer around it.
How do you integrate with our ERP, MES and HRIS?
We work with the standard integrations your source systems offer: REST APIs for modern ERPs (Dynamics 365, AFAS, more recently Exact Online, SAP S/4HANA), IDocs and BAPIs for classic SAP, and ODBC or file exchange for systems that offer nothing else. For MES and SCADA data we work with OPC UA, MQTT or CSV feeds. For HRIS data we integrate via SCIM, REST or an encrypted batch export. See also our page on smart API integrations.
How do you calculate scope 3 emissions?
Under the GHG Protocol, scope 3 splits into fifteen categories: purchased goods and services, capital goods, commuting, upstream and downstream transport, use of sold products, end-of-life treatment and so on. For each category we choose the most reliable data approach: supplier-specific data where available, sector emission factors as a fallback (DEFRA, IEA, Exiobase, ecoinvent) and activity-based calculations for logistics. Every choice is logged and justified in the audit trail for your external auditor.
How does the double materiality assessment work in your platform?
The double materiality assessment has two axes: impact materiality (your effect on people and the environment) and financial materiality (sustainability risks and opportunities for your business). We build tooling to plan stakeholder research, score topics on both axes, set thresholds and document the outcome with supporting evidence. The output is a materiality matrix plus a defence of your choices, which you include in the CSRD report and which your external auditor can accept.
What does the audit trail look like for our external auditor?
Every data point change is logged with a timestamp, user, and old and new value. Every approval in the workflow is recorded. Every calculation can be traced back to the source value, the emission factor used and the rule set that applied at the time of reporting. We provide a separate assurance environment in which your auditor can review everything, ask questions and record approvals without access to production systems. For most audits this is sufficient; we supply additional exports in whichever format your firm requires.
What if the ESRS standards change?
They will. EFRAG is continuing to work on sector-specific standards, and the European Commission has already indicated that it wants to amend or delay parts of the framework. Our approach: the data point register is data-driven, not hard-coded. A new or amended ESRS requirement means adding a data point or updating a calculation rule, with no rebuild. Under ongoing support, we monitor EFRAG updates and process relevant changes in a release cycle.
What determines the cost of a custom CSRD platform?
The biggest cost drivers are the number of source systems we integrate, the complexity of your scope 3 chain, the number of entities in the consolidation and the scope of your materiality assessment. An integration layer on top of an existing SaaS platform is generally considerably lighter than a completely new multi-tenant white-label platform for a consultancy. We only give an honest estimate after the scoping session. We have a page on custom software costs that explains the logic.
How long until we can go live with a first report?
For a well-defined module, for example scope 1 and 2 plus a few S1 data points for a single entity, a first working version can be ready within a few sprints, often with a real ERP integration already in place. A full multi-entity platform with scope 3, materiality tooling, an assurance portal and XBRL export takes several sprints, with a pilot entity as the first delivery and phased scaling afterwards.
Do you work with our IT department and our sustainability consultant?
Almost always. Your IT team provides the connection to source systems and the cloud environment, your sustainability consultant provides the methodological knowledge of ESRS and materiality, and our team builds the software and the integrations. In the final sprints we hand over knowledge so that your own team can manage it, or we continue the management as an enterprise software project with an SLA and monitoring.

Talk to us about your CSRD software.

A no-obligation introductory call of half an hour. We listen to your reporting obligations, your source systems and your materiality context, and give you useful direction, even if a standard SaaS platform turns out to be the better choice. See also custom ERP system for our approach to related data-heavy projects.

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