Tax code lookup — updated in real time from the tax authority
Enter a single tax code → get back the legal name, registered address, managing tax office and operating status, updated in real time from the tax authority. Look up one code or many codes at once in batch, export to Excel, and stay compatible with any software.
From a single tax code, get the full identity record updated in real time from the tax authority. Look up one code or in batch, and export the results to Excel or plug them straight into accounting software, an ERP or onboarding — a great fit for tax agents, accounting firms and invoicing teams.
Why does "real-time updates" matter?
A business's tax registration details do not stay still. Over its lifetime, a company may change its name after a restructuring, move its head office to another district or province, switch its managing tax office, or fall into a suspended, locked or even closed tax-code status. Each of those changes quietly makes the copy of the data you once stored outdated without warning — you never get a notification.
The catch is that invoices and contracts demand information that is correct at the exact moment it is issued. A wrong name or address, simply because you relied on a snapshot from a few months ago, can render an invoice invalid at reconciliation time.
- !Name / head-office address change: an invoice showing the old name or address may be rejected by the buyer, forcing an adjustment or a cancel-and-reissue.
- !Change of managing tax office: when a business moves location, the district/provincial tax office in charge changes — stale data routes filings and reconciliations to the wrong channel.
- !Suspended / locked / closed tax code: extending credit, signing a contract or issuing an invoice to an entity that has ceased operating is a legal and collection risk.
- !CRM / ERP out of sync with reality: wrong identity data spreads through reports, receivables reconciliation and customer records, and is hard to trace back and fix.
How is real-time data different from a periodically synced copy?
Many lookup tools run on a copy of the data synced on a schedule — maybe daily, weekly, or less often. Between two syncs, every change on the tax authority's side has not yet appeared in that copy. You get a result that looks complete but is really a snapshot of the past.
| Aspect | Periodically synced copy | TCONNECT real-time lookup |
|---|---|---|
| Data freshness | Lags behind the sync cycle (possibly by days) | Reflects the status at the exact moment of the call |
| Entity just changed its details | Not updated until the next sync | Visible the moment you look it up |
| Entity just ceased operating | Still shows "active" | Returns the correct latest status |
| When it is safe to rely on | Only correct right after a sync | Correct at the exact business step |
When you look up a code right before issuing an invoice or approving an onboarding, real-time data gives you the correct information at the exact business step, regardless of whether the previous sync happened to be up to date.
Which fields does a lookup return — and what are they for?
From a single tax code, you get the entity's full identity record. What matters is not "which fields exist" but what each field is used for in your workflow:
| Field | Business meaning |
|---|---|
| Legal name | The full, correctly spelled name to put on invoices and contracts — avoiding mismatches that force an invoice adjustment |
| Registered address | The head-office address on the tax registration, used for the "buyer" field on invoices and for legal records |
| Managing tax office | The district/provincial tax office in charge — helps route filings and reconcile with the right counterpart |
| Legal representative | The legal representative (if available) — a reference when signing contracts and running due diligence |
| Operating status | Active / suspended / closed tax code — the signal that decides whether to transact or extend credit |
This set of fields is exactly the raw material for auto-filling onboarding forms, issuing invoices with the correct buyer and business due diligence (KYB) — covered in detail in the sections below.
KYB — know your partner before signing a contract or extending credit
KYB (Know Your Business) is the step of vetting a partner business before establishing a trading relationship. In the Vietnamese context, the core question is usually very practical: does this entity still exist and is it still operating? A real-time tax-code status is a fast, trustworthy answer to that question.
- ✓Before signing a contract: confirm the entity is active and that its name and address match the records the partner provided.
- ✓Before extending credit / selling on account: avoid granting a limit to an entity with a suspended or closed tax code — reducing collection risk.
- ✓When opening a business customer account: cross-check the declared details against tax-authority data right at the registration step.
- ✓Periodic review of the partner portfolio: spot early any entity whose status has changed so you can revisit the trading terms.
A tax-code lookup returns the identity information managed by the tax authority; it is one piece of KYB, not a replacement for your organization's full credit-assessment or compliance process.
Batch lookup, Excel export, compatible with any software
Tax agents, accounting-service firms and outsourced accountants have to handle the tax codes of hundreds of clients and suppliers. Typing each code by hand to check the name, address and status is repetitive, time-consuming and error-prone work. With TCONNECT, you can:
- ✓Look up many tax codes at once: feed in a list of tax codes and get batch results instead of checking one at a time.
- ✓Export results to Excel / Google Sheets: paste a list, get back a full table of details, easy to cross-check and archive.
- ✓Compatible with any software: plug into accounting software, an ERP, invoicing software or onboarding — no tool is off-limits, including Excel.
A tax agent needs to review 300 clients at the start of the period. Instead of looking up each code by hand, they paste the list of tax codes into Excel, run a batch lookup and get back the updated names, addresses, tax offices and statuses — cutting hours of work down to minutes, and more importantly eliminating typing errors when processing large volumes.
Review your start-of-period tax-code list in three steps
The most familiar approach for an accountant: start and finish inside the spreadsheet, without leaving the tool you use every day.
| Step | What you do | What you get back |
|---|---|---|
| 1. Prepare | Paste the tax-code column of all clients / suppliers into the spreadsheet | An input list of tax codes |
| 2. Batch lookup | Run the lookup for the whole list in one pass | A table of names, addresses, tax offices, statuses |
| 3. Reconcile & act | Filter the entities that changed details or ceased operating | A list to update / prioritize |
With a table output, you can immediately filter the rows with an unusual status and handle them first — instead of opening each record to check manually.
Plug into every business workflow
It is the same lookup query, but the value lies in where it connects into your workflow:
- ✓Auto-fill onboarding forms: the customer enters a tax code and the system fills in the name, address and tax office — fast, low-error, and less typing for the customer.
- ✓Issue invoices with the correct buyer: pull the exact name and address so the invoice is valid from the start, avoiding adjustments or cancellations. See also Invoice Hub — connect to multiple e-invoice providers.
- ✓Reconcile suppliers: check whether the seller details on an inbound invoice match the tax authority's data.
- ✓Enrich CRM / ERP data: standardize business details from a single tax code, keeping customer records accurate.
The customer enters one tax code, the form fills in the rest
A good onboarding experience is one where the customer types as little as possible. Instead of making customers hand-enter the company name, registered address and tax office — long details that are easy to mistype — you only need one field: the tax code.
- ✓The customer enters a tax code → the system runs a lookup → auto-fills the name, address and tax office into the remaining fields.
- ✓Fewer data-entry errors: the information comes from tax-authority data, not from whether the customer typed it correctly.
- ✓Higher form-completion rate: fewer fields to fill → fewer customers abandoning midway.
- ✓The filled-in information is real-time, correct at the moment the customer registers — not an outdated copy.
Reconcile supplier details on inbound invoices
When receiving an inbound invoice, accountants need to know whether the seller details are correct: do the name, address and tax code on the invoice match the data managed by the tax authority, and was that entity operating at the time the transaction took place.
- ✓Verify the seller: cross-check the name and address on the invoice against the real-time lookup.
- ✓Check the status: spot early any supplier that has suspended or closed its tax code.
- ✓Standardize supplier data in your books for more accurate receivables reconciliation and reporting.
Combined with looking up inbound invoices from the tax portal, you get a fuller picture of your inputs. See also API to look up inbound invoices from the tax portal.
Manual lookup vs. API — an in-depth comparison
| Criterion | Manual lookup | TCONNECT lookup API |
|---|---|---|
| Speed | Hand-entered, one entity at a time | Automatic, returned in a single call |
| Accuracy | Easy to mistype or copy into the wrong field | Correct per the tax authority's data |
| Data freshness | Depends on the source, easy to use a stale copy | Real-time at the moment of the call |
| Large scale | Not feasible with hundreds of entities | Batch processing via integration |
| Auto-fill form / issue invoice | Manual step by step, easy to miss | Auto-fills straight into the workflow |
| Auditability | Hard to keep a trail, hard to re-check | Export to Excel / plug into an ERP to archive |
Simple integration: pass a tax code, get the details
The lookup endpoint is designed to be easy to integrate: you just pass the tax code as a parameter, with no data encryption or complex payload to build. It fits into an onboarding form, an invoicing flow, or an accounting team's batch-review job.
- ✓One parameter: call the lookup with the very tax code you need to check.
- ✓Structured results: the identity fields are ready for your system to reuse.
- ✓Part of the TCONNECT Open API suite: the same integration as payments and e-invoicing.
See how to call it and the returned fields in the tax-code lookup API documentation. Your team can integrate and test quickly without changing your existing infrastructure.
Integrate tax code lookup
See the tax-code lookup API documentation, or contact us for integration advice.
TCONNECT is an infrastructure platform providing payment APIs (VietQR, payment gateway, POS, Soundbox) and e-invoicing through a single integration, built for PSPs, SaaS, ERPs and businesses in Vietnam.