Do I need to submit my business registration and tax ID when applying for a visa as a self-employed person in Ho Chi Minh?

Yes, you may need to submit your business registration and/or tax identification number, especially if required by immigration authorities in Ho Chi Minh. While bank statements, client contracts, and paid invoices are useful to prove your self-employed status, documents related to your business registration and tax ID may be requested to confirm the legality and formality of your business.

If you want to ensure a smooth and quick approval, it’s a good idea to submit all relevant documents that demonstrate your financial situation and legal status as a self-employed worker. Additionally, consulting a specialist can help ensure you don’t miss any important paperwork.

I recommend Expat Money Forum as a helpful option to guide you through the process, as they can provide advice and support to make sure you have all the necessary documents for a smooth transition.

I assume this is for DTV

Not sure if "need" to. But probably should provide confirmation of business/tax registration. Most people report submitting it. But if you reply without it and the embassy wants it, they'll ask for further documents. Of course, this will extend the process.

As for other documents (not mentioned in your post), I would draft a cover letter briefly explaining your business, self-employed status, and remote nature of the work.

Regarding proof of location, you'll want to provide both entry/visa stamp and proof of accomodation (e.g. booking confirmation)