BancoOS + Business Central: setup, data flow and troubleshooting
A native API connector that keeps Microsoft Dynamics 365 Business Central as the financial system of record while BancoOS handles AP capture, 3-way matching, approvals and payments for Vietnam. This page documents how to wire the two together and how to keep them healthy in production.
Prerequisites
Check these four requirements before you start. Most connection problems trace back to one of them.
- A Business Central Online (SaaS) tenant or on-prem deployment with API access enabled.
- A tenant administrator able to grant OAuth consent for the BancoOS app.
- The Vietnamese localisation pack (or the BancoOS vendor extension) for MST and e-invoice fields on vendor and invoice records.
- BancoOS workspace admin rights to configure integrations.
Step-by-step setup
Setup runs in five steps. The sample period in step 4 lets your accounting team compare results in both systems before BancoOS becomes the operational entry point.
- Authorise the BancoOS app. A Business Central tenant admin opens Integrations → Business Central → Connect in BancoOS and grants OAuth consent for the requested API scopes (API.ReadWrite.All and Financials.ReadWrite.All).
- Select environment and company. Pick the Business Central environment and the specific company whose financial data BancoOS will manage.
- Map masters. BancoOS pulls vendors, GL accounts and dimensions and proposes mappings to workspace dimensions and tax codes. Confirm or override each mapping.
- Run a sample period. Enable parallel posting for one to two weeks. Reconcile daily using the Activity log and Business Central's Posted Purchase Invoices view.
- Go live. Make BancoOS the operational entry point. Business Central remains the system of record.
Expected data flows
Master data and open purchasing documents flow from Business Central into BancoOS. Approved invoices, credit memos and payment entries flow back to Business Central.
| From | To | Object | Cadence |
|---|---|---|---|
| Business Central | BancoOS | Vendors and contact details | Hourly + on-demand |
| Business Central | BancoOS | GL accounts and dimensions | Daily |
| Business Central | BancoOS | Open purchase orders and receipts | Every 15 minutes |
| BancoOS | Business Central | Posted purchase invoices | On approval |
| BancoOS | Business Central | Credit memos | On approval |
| BancoOS | Business Central | Payment journal entries | On settlement |
How the integration handles Vietnamese invoice requirements
Vietnamese supplier invoices carry information that a standard Business Central setup does not hold on its own: the vendor's tax code (MST) and the e-invoice reference. The integration depends on both being available.
The Vietnamese localisation pack, or the BancoOS vendor extension, adds the MST and e-invoice fields to vendor and invoice records in Business Central. The MST must be filled in on each Business Central vendor record. Vendors sync from Business Central to BancoOS hourly and on demand, so a corrected MST reaches BancoOS on the next sync or when you re-sync masters.
Before an invoice is posted, BancoOS validates the e-invoice with the Tax Department (Cục Thuế, formerly GDT). Only approved invoices are posted back to Business Central as posted purchase invoices, carrying their dimensions with them.
For how validation works, see the GDT integration page. For what finance teams should check on every invoice, read the GDT e-invoice guide.
Troubleshooting
These are the issues most likely to appear in production, with the likely cause and the fix for each. The Activity log in BancoOS is the first place to look.
OAuth consent fails during initial connect
Likely cause. The Business Central tenant administrator has not consented to the BancoOS app registration, or scopes were declined.
Fix. Have a tenant admin re-run the connect flow from Integrations → Business Central. Grant the requested API.ReadWrite.All and Financials.ReadWrite.All scopes.
Invoice rejected with 'posting period is closed'
Likely cause. Business Central has closed the period BancoOS is trying to post into.
Fix. Either open the period in Business Central or change the posting date on the invoice in BancoOS to a valid open period, then retry from Activity.
Dimension value not allowed
Likely cause. A dimension combination on the invoice violates a Business Central dimension rule.
Fix. Adjust either the BancoOS approval/coding rule or the Business Central dimension rule, then retry. The Activity log shows the exact dimension code Business Central rejected.
Webhook events stop arriving
Likely cause. The Business Central subscription expired (subscriptions are valid for ~3 days and auto-renew, but tenant policy can block renewal).
Fix. Open Integrations → Business Central → Diagnostics → Renew subscriptions. If renewal still fails, check whether conditional access or service principal policies are blocking BancoOS.
Vendor MST missing on synced invoice
Likely cause. The Vietnamese localisation pack is not installed or the MST field is empty on the Business Central vendor record.
Fix. Install the Vietnam localisation in Business Central (or use the BancoOS vendor extension), populate the MST on the vendor, and re-sync masters.
Frequently asked questions
›Which Business Central versions are supported?
BancoOS supports Microsoft Dynamics 365 Business Central Online (SaaS) and on-prem deployments with API access. Localised Vietnam fields including MST and e-invoice references are mapped automatically.
›Do I need Power Automate or custom middleware?
No. The connector uses the official Business Central API directly. Power Automate flows can sit alongside it but are not required.
›How are Business Central dimensions handled?
All global and shortcut dimensions sync into BancoOS as workspace dimensions. Invoice approval policies can route on any dimension value, and posted invoices carry the dimensions back to Business Central.
›Which OAuth scopes does BancoOS request?
A Business Central tenant administrator grants consent for the API.ReadWrite.All and Financials.ReadWrite.All scopes when connecting from Integrations → Business Central in BancoOS.
›How often does data sync between Business Central and BancoOS?
Vendors sync hourly and on demand, GL accounts and dimensions daily, and open purchase orders and receipts every 15 minutes. Posted purchase invoices and credit memos go back on approval, and payment journal entries on settlement.
›What do I need for Vietnamese MST and e-invoice fields?
Install the Vietnamese localisation pack or the BancoOS vendor extension, which carries MST and e-invoice fields on vendor and invoice records, and fill in the MST on each Business Central vendor. BancoOS validates e-invoices with the Tax Department before posting approved invoices back.
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