Zambian VAT-registered businesses must transmit sales documents to the Zambia Revenue Authority's Smart Invoice service and print the returned fiscal identifiers on the customer's copy. Dynamics 365 Business Central posts a clean Sales Invoice Header with VAT posting setup, currency and dimensions all correct — and then stops. There is no field to hold a Smart Invoice reference, no verification QR data, no retry when the ZRA endpoint or the local Smart Invoice device is unreachable, and no way to tie a posted credit memo back to the fiscal reference of the invoice it corrects. Finance teams end up keying the same invoice a second time into a separate ZRA portal or VSDC utility, reconciling two sets of numbers at month end, and discovering mismatches only when an auditor asks.

ECOSIRE builds a Business Central AL extension that closes that gap inside the ERP. Table extensions on Sales Invoice Header, Sales Cr.Memo Header and Service Invoice Header carry the fiscal state: Smart Invoice number, ZRA-assigned identifiers, device/branch reference, signature or verification payload, transmission timestamp and status. An event subscriber on the posting codeunits (OnAfterPostSalesDoc and equivalents) enqueues the document rather than blocking the user, so posting stays as fast as it is today. A dedicated transmission codeunit builds the ZRA payload from your master data — item classification and tax-type codes held on Item and Item Category, TPIN and branch codes on Company Information and Customer — signs and posts it to the Smart Invoice API or local device endpoint, and writes the response back onto the posted document.

Because the ZRA service will reject payloads, rejection is a first-class flow, not an error log. A Smart Invoice Log table records every attempt with request, response, HTTP status and error code, and a Fiscalization Worksheet page lets a finance user filter failed documents, read the ZRA message in plain language, correct the underlying master data, and re-submit — with an idempotency key so a retry can never produce a duplicate fiscal record. A job queue entry drains the pending queue on your chosen interval and escalates aged failures; credit memos carry the originating invoice's fiscal reference so ZRA sees a correction rather than an unrelated document. The same posting produces both outputs the regulation expects: the human-readable invoice report, extended with the fiscal block and verification QR, and the machine payload retained for the statutory archiving period in a locked, non-editable log.

Everything ships as versioned AL source with permission sets separating who may post, who may re-transmit, and who may only read the log. Setup lives on a dedicated Smart Invoice Setup page with per-environment endpoints, so sandbox and production never share credentials, and secrets are held in isolated storage rather than plain setup fields. API pages expose fiscal status over REST API v2.0 / OData v4 for Power BI reporting or a Power Automate alert, and Dataverse virtual tables are available where a wider Power Platform estate needs the same data. The extension targets your current Business Central release wave and runs on SaaS online tenants as a per-tenant extension or AppSource-track app, and on-premises where you host it yourself.

This is build-to-order, not a marketplace download. You request a quotation, we run a scoping call to confirm your document types, VAT and tax-type mapping, branch/device topology and ZRA registration status, and we quote a fixed scope. Typical delivery is one working week from confirmed scope. We build against your Business Central version, deploy to your sandbox first for UAT against the ZRA test environment, then promote to production with a documented rollback. You receive the AL source and a git repository so the extension remains yours.