E-Invoicing Functional consultant

Job Title: E-Invoicing Functional consultant

Location: Ireland/United Kingdom (Remote)

Employment type: Contract

Detailed Job Description:

Purpose of the role:

This role exists to give the client a single, authoritative subject matter expert on European e-Invoicing for the duration of the solution design phase.

The architect will work alongside the client's own architecture, ERP and finance teams to define the overall solution architecture for the e-Invoicing programme, and to ensure that the designs produced comply with the legislative tax mandates in every jurisdiction the client operates in. The emphasis is on regulatory and architectural depth rather than platform build: the person in this role sets the direction that the technical and functional architects then implement.

This is a consultative, client-facing appointment. Much of the value is delivered through advice, challenge and design rationale in the room with senior stakeholders, not through configuration or code.

Programme context:

The client is a multi-format retail group operating across several European jurisdictions, with a heterogeneous application estate. The e-Invoicing programme must bring disparate ERP and retail systems into compliance with tax authority mandates while routing compliant documents through the Peppol network via cloud Middleware.

Practically, this means the target architecture has to reconcile three things at once: what each tax authority requires, what the existing systems can produce, and what the Middleware layer can reliably transmit and audit. Designing for one jurisdiction in isolation is not sufficient - the architecture needs to accommodate several regimes concurrently and absorb further mandates as they come into force.

Key responsibilities:

Regulatory and jurisdictional advisory

• Advise on e-Invoicing and digital reporting models across the EU jurisdictions relevant to the client's footprint, including the specific requirements applying in Ireland, Spain and the United Kingdom.
• Maintain and communicate a current view of tax authority mandates, their scope, their timelines and the practical obligations they place on the business.
• Distinguish clearly between clearance and post-audit models, and set out the architectural consequences of each.

Solution architecture and design

• Define the target solution architecture for the e-Invoicing programme and articulate the design principles that sit behind it.
• Produce solution designs that are demonstrably compliant with the legislative requirements of each in-scope jurisdiction.
• Set the approach for integrating the client's ERP and retail systems with Peppol Access Providers through cloud Middleware, including message routing, audit trails and error handling.
• Translate regulatory requirements into practical architectural decisions, making the trade-offs explicit where full compliance and operational simplicity pull in different directions.

Stakeholder engagement

• Work directly with procurement, finance, digital and IT stakeholders, and support them in making informed design choices.
• Present and defend design decisions to senior stakeholders, including where the recommended option is not the cheapest or the fastest.
• Act as the point of escalation for questions of regulatory interpretation during the design phase.

Delivery enablement

• Guide the wider delivery team on compliance requirements as the programme progresses, so that build activity stays aligned to the agreed architecture.
• Identify supplementary skills or capacity the programme will need beyond those already provisioned, and flag them early.
• Transfer knowledge to the client's permanent teams so that compliance understanding is not dependent on a single individual once the engagement ends.

Required experience:

• Jurisdictional depth - Demonstrable expertise in EU e-Invoicing across multiple jurisdictions, evidenced by delivery rather than familiarity.
• Peppol and network expertise - Strong working knowledge of Peppol and the four-corner model, including Access Point integration, SMP and SML lookups and routing behaviour.
• Message standards - Fluency in EN 16931 and the universal formats built on it, notably UBL and UN/CEFACT CII.
• Compliance strategy - Command of Continuous Transaction Control models, digital signature obligations and country-specific statutory requirements, together with a clear view of the direction of travel under ViDA.
• Middleware and API governance - Experience designing asynchronous call-backs, audit trails and retry mechanisms across B2B or B2G gateways, ideally using cloud Middleware services.
• Multi-country design - Experience advising a multi-country organisation on designing for several regimes at once, rather than delivering a single-country implementation.
• Architecture practice - Solution architecture experience gained in a regulated or finance-adjacent context, where design decisions carry compliance consequences.
• Stakeholder presence - Confident and credible with senior stakeholders. This is an advisory, client-facing position and the ability to hold the room matters as much as the technical knowledge.