Since 1 July 2025, Vietnam has 34 provinces and centrally run cities and no district level of government. The tax administration was rebuilt around that map in three tiers: the Tax Department (Cục Thuế) at central level under the Ministry of Finance, provincial and city tax offices (Thuế tỉnh, thành phố), and grassroots tax offices (Thuế cơ sở) that serve groups of communes and wards. Every company is managed by one of these offices, and that office is where its returns are received, its refunds are processed and its desk reviews begin.
For a foreign-invested enterprise (FIE), the practical consequence is simple but easy to miss: the office printed on your old correspondence may no longer exist under that name, and the office that manages you now may be a different tier. Before sending a letter, requesting a refund or answering a notice, confirm who manages you today. The rest of this guide explains how.
The three tiers and what each one does
| Tier | Vietnamese name | Typical role for a company |
|---|---|---|
| Central | Cục Thuế | Policy guidance, national systems (e-tax, e-invoice), management of certain large taxpayers, answers on questions with national effect |
| Provincial / city | Thuế tỉnh, thành phố | Directly manages many medium and large enterprises in the province, handles refunds and audits within its remit, coordinates the grassroots offices |
| Grassroots | Thuế cơ sở | Directly manages many smaller enterprises, household businesses and individuals in its area; front-line contact for registration and daily queries |
Which tier manages a given company is decided by the tax authority under its own allocation criteria, not by the company. Size, sector, location and the kind of taxes involved all play a part, and allocations can change. Do not assume that a large FIE is automatically at provincial level, or that a small representative-style subsidiary is at grassroots level: check.
The number of grassroots offices differs sharply between provinces. Ho Chi Minh City, after absorbing neighbouring provinces in the 2025 merger, is served by 29 grassroots tax offices. Smaller provinces have far fewer.
How to confirm your managing office
- Search the taxpayer information lookup of the tax authority by your tax code (mã số thuế). The result shows the registration status and the managing tax office.
- Check your e-tax account. Notices sent to you through the account carry the name of the issuing office. If the lookup and recent notices disagree, ask before acting.
- Check each branch separately. A branch or business location in another province has its own tax code and may be managed by a different office from the head office.
- Record the result in your compliance file with the date you checked. When an auditor or your parent company asks which office you report to, you will have evidence rather than memory.
Our sister site TrungTamThue.com (in Vietnamese) follows the new boundaries province by province, which helps when an address that used to sit in a district now falls under a differently named office.
Addresses after the province merger
The merger changed many administrative addresses without anyone moving. A factory that sat in a district of one province may now be in a ward or commune of a merged province with a different name. This creates three small but persistent problems:
- Your own invoices. The address on your e-invoices should match what the tax authority holds for you. If your registration still shows the old address, decide with your adviser whether and when to update it under the current tax registration rules; Circular 90/2026/TT-BTC on tax registration took effect on 1 July 2026 and is the document to read for procedures from that date.
- Supplier and customer master data. Addresses in the ERP will drift from what appears on counterparties' invoices. A mismatch in the address alone does not normally make an invoice invalid, but it complicates matching. Rely on the tax code as the key, not the address.
- Group reporting. Regional teams abroad often keep a list of Vietnamese entities by "city". Several of those cities may now be one province, and one of your entities may have changed its managing office without changing its premises.
When your managing office changes
Allocations move: after the 2025 reorganisation, after a change of registered address, or when the authority rebalances its workload. A change of managing office does not reset anything on the company's side — returns, balances and open matters carry over — but a few things deserve attention in the first months:
- Open refund applications. Confirm which office is now processing the file and whether any additional documents requested by the previous office still need to be supplied.
- Outstanding notices. A request for explanation issued by the previous office still has to be answered. Ask where to send the reply rather than letting the deadline pass while the question of jurisdiction is sorted out.
- Balances in the e-tax account. Check that overpayments, amounts carried forward and late-payment interest calculations appear correctly after the move. Transfers between offices occasionally leave an amount showing as outstanding when it has already been paid.
- Contact details. Update the name of the office, the officer in charge if one is assigned, and the address for paper correspondence in your internal compliance file.
None of this requires a formal request from the company. It requires someone to look, within a month or two of the change, so that a small administrative gap does not become a disputed debt a year later.
Dealing with the tax office in writing
Most interaction now happens through the e-tax system: returns, payments, refund applications and many registration changes are submitted electronically and signed with the company's digital signature. For anything that is not a standard form, companies write an official letter (công văn) in Vietnamese, signed by the legal representative or an authorised person and stamped where the company uses a seal.
A few habits save time:
- Write in Vietnamese. An English version can be attached for your own records, but the Vietnamese text is the one the office acts on.
- Quote document numbers in full — for example Circular 80/2021/TT-BTC rather than "Circular 80" — and give the tax period concerned.
- Keep authorisations current. If an accountant or a tax agent deals with the office on your behalf, the authorisation must name the person and scope. Staff changes are the most common reason an authorised visit is refused.
- Keep the receipt. For electronic submissions, the system acknowledgement is your proof of filing date; save it with the submission.
Asking for guidance, and how much to rely on it
A company can ask its managing office, or in some cases the central Tax Department, for written guidance on how a rule applies to its situation. The reply comes as an official letter. Such letters are useful: they show how the authority reads a rule, and many are published and cited by practitioners.
Two cautions. First, a guidance letter answers the facts described in the request. If your facts differ, the letter does not protect you, and a letter addressed to another company is persuasive at best. Second, guidance letters interpret legal documents; they do not override them. When the underlying decree or circular changes — as it did for tax administration, e-invoices, personal income tax and related-party transactions with the documents effective 1 July 2026 — older letters need to be re-read against the new text.
Describe the facts completely and neutrally when you ask. A request drafted to lead to a particular answer tends to produce a reply that will not hold up if the facts are later examined in an audit.
Other authorities you will meet
- Customs — import and export duties, import VAT, processing and export-manufacturing regimes, and post-clearance audits.
- Social insurance agency — compulsory social, health and unemployment insurance on payroll.
- Business registration office of the province — the enterprise registration that generates your enterprise code, which is also your tax code.
- Investment registration authority — the investment registration certificate for FIEs, which is where project incentives originate.
Keep the chain in mind: a change on the investment or enterprise registration side (address, capital, business lines, legal representative) usually has a tax registration consequence, and it is the company's job to make sure the tax authority's record follows.
Frequently asked questions
Did our tax code change when the provinces merged?
No. The province merger changed administrative units and the tax office structure, not company tax codes. Your enterprise code remains your tax code; what may have changed is the name of the office that manages you and the wording of your address.
Can we choose to be managed by the provincial office instead of the grassroots office?
No. Allocation between tiers is decided by the tax authority under its own criteria. If you believe the allocation is wrong or is causing practical problems, raise it with the office that currently manages you.
Our branch is in a different province. Who manages it?
A branch with its own tax code is usually managed by the tax office where it is located, which may differ from the head office's. Check each branch in the taxpayer lookup rather than assuming it follows the head office.
Is an English letter to the tax office acceptable?
Official correspondence should be in Vietnamese. Keep an English translation for internal use and for your parent company, but the Vietnamese version is the one that is filed and acted on.
Is a guidance letter issued to another company binding for us?
No. A guidance letter answers the facts in that company's request. It can indicate how the authority reads a rule, but it does not bind the authority in your case, and it does not override decrees or circulars.
Who should sign letters to the tax office?
The legal representative, or a person authorised in writing for that matter. Make sure the authorisation is current, names the person and covers the scope of the letter or visit.
