Nigeria's FIRS e-invoicing regime turns invoicing from a printing exercise into a transmission obligation. Every sales invoice and credit memo has to leave Business Central as a structured, FIRS-aligned payload carrying seller and buyer TIN, the correct VAT and withholding treatment per line, currency and FX detail, and a document reference that survives correction cycles. Standard Dynamics 365 Business Central gives you posted sales documents, VAT posting setup and a report layout — but nothing that builds the FIRS document structure, authenticates and submits it, stores the returned authority identifiers against the posted document, or drives a rejection back into a controlled correction. Teams bridge that gap with a spreadsheet and a portal login, and the ERP and the tax authority start disagreeing the moment someone re-keys a figure.

We build an AL extension for your tenant that closes the loop inside Business Central. Table extensions on Sales Invoice Header, Sales Cr.Memo Header and Customer carry the FIRS fields — TIN, buyer identification scheme, submission status, authority reference, timestamp and raw response — so compliance state lives on the document, not in a side system. A mapping layer translates your existing master data into FIRS terminology: VAT Business and VAT Product Posting Groups to tax categories and rates, item and G/L lines to the required classification, Units of Measure to the expected code list, and Currency Exchange Rate data to reporting-currency figures. Nothing is hard-coded — mappings live in setup tables your finance team maintains, and validation refuses to submit a document with an incomplete mapping rather than sending something the authority will bounce.

Transmission runs through codeunits that build the payload, apply the required signing and authentication, call the FIRS endpoint over HTTPS with retry and timeout handling, and persist the full request and response for audit. Submission is driven by a Job Queue Entry, so posting stays fast and an authority outage never blocks a sale: documents queue, submit and reconcile on their own schedule, with a dedicated FIRS Submission Log page showing status, attempt count, error text and the raw payload. One posting produces both the machine format for the authority and the human-readable document — the customer-facing PDF carries the identifiers and verification data returned by FIRS, so what the buyer receives matches what was filed. Rejections land in a work queue: the extension surfaces the authority's error, blocks blind re-sends, and drives the corrective document with the original reference preserved.

Technically it stays upgrade-safe. We subscribe to events on the standard posting codeunits rather than modifying base application objects, ship dedicated permission sets so submission and correction rights are separable from ordinary sales roles, and expose submission status through API pages (REST API v2.0 / OData v4) so Power BI, a Power Automate flow or a Dataverse-connected app can read compliance state without a database hop. We target current Business Central release waves and support both online (per-tenant extension, or AppSource-track packaging if you intend to publish) and on-premises deployments.

This is built to order, not downloaded. After a short scoping call we confirm your Business Central version and deployment model, your Nigerian entity structure and TIN setup, which document types are in scope, your VAT and WHT treatment, and how FIRS credentials and endpoints are provisioned to you. We then build against your exact version, test on your sandbox with your real chart of accounts and customer data, run UAT with your finance team, and deploy with a rollback plan. Typical delivery is one working week from confirmed scope, depending on document types, integration surface and how many legal entities are involved. You receive the AL source, the git repository, technical and user documentation, a training session and a post-go-live support window — and because regulatory schemas move, we agree the update path for schema and endpoint changes as part of the engagement rather than leaving you to discover them at filing time.