Open a contact, then More → Update (Edit contact details). That dialog is only for people you talk to — not the legal buyer on the VAT invoice.
See Customers for types, MST lookup, and how to create.
#What you can edit
Update lets you change:
- Contact person
- Phone (with country code)
Those fields are for follow-up. They sit next to the legal identity. They do not replace legal name, address, or MST on an issued invoice.
#What you cannot edit
The Update dialog does not change:
- Type — Vietnam, Foreign, or Individual. Set when you create.
- Legal name, address, and MST on a Vietnam contact. Those come from the tax registry.
- Company name (foreign) or full name and CCCD / passport (individual). Entered at create.
- The system contact Bán cho người tiêu dùng. Update is disabled. You cannot delete it either.
To refresh a Vietnam contact’s name, address, or taxpayer status, use Refresh from Tax Authority on the contact page — not Update. The registry is the source, not a typed correction.
#Why
A Hóa đơn GTGT must show the buyer as the tax authority knows them. If you could rewrite MST or legal name by hand after invoices exist, the contact would drift from the XML you already signed. Issued invoices cannot be cancelled. A wrong buyer means adjust or replace.
Contact person and phone can change when someone leaves the company. The MST does not.
#Delete
More → Delete is off when:
- The contact is already on an invoice or quotation — fix or keep those documents first
- It is the system contact
Leave the record if it has history. Create a new contact if the buyer is a different legal unit (new MST).