If you work from home in San Francisco, the city's business registration asks for two addresses. The location address is where you do business, so your home goes there. The mailing address can be any valid mailing address, including a postal box. Both addresses appear on the city's list of public information.
For this post, we read the registration page of the San Francisco Office of the Treasurer & Tax Collector (TTX), the tax office that runs business registration. We also read its account update page, its address change form, and two city guides. Then we counted rows in the city's open data on October 17, 2026.
Which two addresses does San Francisco business registration ask for?
The TTX registration page asks for a business mailing address and an address for each place you do business. The application also asks for an address for each owner. Each field has a different job.
| Field on the application | What TTX says goes there | Can a mailbox go there? | On the TTX public list? |
|---|---|---|---|
| Mailing Address | The "ONLY address" for TTX documents, PINs, renewal notices and refunds | Yes. TTX accepts "Any valid mailing address (including a postal box)" | Yes |
| Location Address | "The address of each location in San Francisco where you do business" | No. A location is where business is conducted | Yes |
| Owner Address | "the mailing address for each owner" | The page asks for a mailing address here too | Not on the list |
The registration page says a business "can only have one mailing address." Locations work differently, because each location gets its own entry. TTX also asks you to list each location name, fictitious business name (FBN) or DBA ("Doing Business As") name as a separate location.
The owner address field comes with a reminder. TTX notices and communication "will ONLY be sent to the business mailing address provided on the Business Identification page."
Can the mailing address be a private mailbox or a P.O. box?
Yes, under the TTX definition of the field. The registration page gives the full rule:
"Mailing Address - The business mailing address is the ONLY address to which this office will mail documents and correspondence including personal identification number (PIN) to file and pay taxes, business licenses, notifications to renew your business registration, and refunds. Any valid mailing address (including a postal box) is acceptable. A business can only have one mailing address. This address does not need to be located in San Francisco."
The page adds that TTX "validates mailing addresses against a United States Postal Service database." If the check fails, TTX says it will prompt you to review the address. The page also says "you may continue without making additional changes to the address you entered."
A private mailbox address carries a PMB (private mailbox) number at the street address of a mail receiving business. The TTX page doesn't say how its USPS check treats PMB addresses. San Francisco's own data does show them in use. On October 17, 2026, we counted 393 current locations with "PMB" in the mailing address field. We also counted 6,880 with a P.O. box written there.
The address doesn't have to be in the city or even in California. In the same snapshot, 13,320 current locations had a mailing state other than California.
What counts as a business location if you work from home?
The TTX account update page defines the term in one line: "Locations are the specific sites where business is conducted." If your desk is in your San Francisco apartment, your apartment is the business location.
The TTX address change form treats a home as a normal kind of location. Question 2 on the form asks, "Will this location be operated from a home or other residential location". Your answer matters for the First Year Free program. According to the form, a location "may qualify" if you answer yes to the commercial use question and no to the home question. A home location doesn't meet that test.
The city guide to home-based businesses says "You can get a separate business address or you can use your personal address for your registration." The guide doesn't say which field it means. Read with the TTX definition, a separate address fits the mailing field, or a real second workplace fits the location field. A mailbox isn't a place where you conduct business, so we don't suggest it for the location field.
Who has to register? The TTX page says the Business and Tax Regulations Code "generally requires that every person engaging in business within the City, regardless of whether the business or person is subject to taxation, must register within 30 days after commencing business within the City." The page lists tests that trigger registration. Two of them are a fixed place of business in San Francisco, and work done in the city on all or part of any seven days in a tax year.
Home work has its own limits under city planning rules. The city guide says, for example, "You cannot have clients coming to your home." The guide also says you "cannot use more than 1/3 of the total floor area of the unit for commercial purposes." Some practices, such as acupuncture, are exceptions to the client rule.
Which registration details does San Francisco make public?
The TTX registration page lists what becomes public. The page says the information "will be available to the public via DataSF.org, listed on your registration certificate, and/or available through public record requests". DataSF.org is the city's open data site. The page lists 10 items:
- Business/Ownership Name
- Business Start Date
- Mailing Address
- Business Account Number
- DBA Name
- Business Activity Code / NAICS code
- Third party tax collection
- Location Address
- Location Start Date
- License code (if applicable)
After the list, the page says "All other information provided is considered confidential and treated in accordance with applicable laws." Owner addresses aren't one of the 10 items. The page doesn't say which items go to DataSF and which appear only on the certificate or in records requests. So we checked the DataSF dataset itself.
The dataset is called "Registered Business Locations - San Francisco," and TTX publishes it. Each location is one row. The columns include the owner name, the DBA name, the location street address and the mailing address. One more column, location, holds "The latitude and longitude of the business location for mapping purposes." Other columns place each location in a neighborhood and a supervisor district.
A home location address therefore usually shows up as a street address and as a point on a map. A mailbox in the mailing field doesn't remove that row. What a mailbox does is keep your home from appearing a second time, in the mailing column.
We covered the state-level version of this question, for state LLC filings, including California, in which LLC address slot becomes public record.
How many San Francisco businesses use the same address in both fields?
We counted rows in the DataSF dataset on October 17, 2026, through its public query interface. We treated a location as current when its location end date, DBA end date and administrative closure field were all empty.
| What we counted | Rows | Share |
|---|---|---|
| All rows, including closed locations | 368,379 | |
| Current locations | 127,567 | |
| Current locations with the same mailing and location address | 57,691 | 45.2% of current |
| Current locations with " APT " in the location address | 8,785 | |
| Of those, same address in both fields | 5,698 | 64.9% |
| Current locations that started on or after January 1, 2026 | 11,555 | |
| Of those, same address in both fields | 7,306 | 63.2% |
Our "same address" test was an exact text match after we set both fields to upper case. The test misses pairs written two ways, such as "St" and "Street." Every share above is therefore a lower bound.
We used "APT" as a rough stand-in for homes. An apartment written as "#" or "Unit" doesn't match, so the 8,785 count is also a floor. Among those apartment locations, about two out of three used the apartment as the mailing address too.
The data also holds 151 current locations with "PMB" in the location field. The TTX definition of a location doesn't support that entry, and we don't suggest it.
How do you change your mailing address after you register?
TTX handles address changes through its Business Account Update page. The page says you need "your seven (7) digit Business Account Number (BAN), the last four (4) of your Taxpayer Identification Number (FEIN or SSN), and your eight (8) character Online PIN." The page adds that "it may take 24-48 hours for the change to be reflected."
An old mailing address doesn't pause your duties. The same page says "Taxpayers and license holders will be liable for any tax, fee or license obligation even if the contact information is not current." The registration page also lists "Your mailing address is not up to date" as a reason a certificate can't be printed.
Your Business Registration Certificate goes to the mailing address. The registration page says the certificate "must be conspicuously displayed at your place of business", so plan to carry it from the mailbox to where you work.
DataSF doesn't take changes. The DataSF FAQ says "In order to change your business address, you must do so with the Office of the Treasurer & Tax Collector." The FAQ also says an address change takes time to show up in the dataset.
If you use a fictitious business name, there is a second filing. TTX says that after you register with its office, "all businesses with one or more locations in San Francisco and using an FBN must register the name with the County Clerk." We read the statewide FBN form in California business forms and a private mailbox. Our Los Angeles DBA and business tax address post covers how one county runs the same filing. The city in your mailing address may differ from the city that governs your business, which we covered in which city your California business address is in.
How an Auteur address fits
We sell virtual mailboxes, so read this section as the seller's view. Auteur is in pre-launch, and your exact street address is assigned the day your city opens. San Francisco is one of our nine US cities.
An Auteur address can go in the TTX mailing address field. If you work from home, our address can't be your business location, and our address doesn't keep your home out of the public data. Neither plan gives you a registered agent address or the real place of business a licensing agency asks for. Every address we offer goes through USPS Form 1583 before mail can arrive in your name.
Mail from TTX is mail for your business. The Virtual Business Address receives mail in a business or trade name. The Virtual Mailing Address is for personal mail, in individual names only.
Both plans include a photo of every envelope as it arrives. Opening and scanning a piece is one flat fee, only when you ask. Henry, our AI assistant, explains each letter you ask us to open. Pricing comes by email with the next steps, and our fair use policy lists our fees and limits.
For a business name in San Francisco, get your Virtual Business Address. For personal mail only, choose the Virtual Mailing Address. Ordering is free, and nothing is charged today. Our guide to business licenses explains how city registration fits with other licenses, and using your home address as a business address covers the wider choice.
FAQ
Do I have to register if I freelance from home in San Francisco?
If you engage in business in San Francisco, TTX says the code generally requires you to register within 30 days of starting. The rule applies whether or not you owe tax. One TTX test is work done in the city on all or part of any seven days in a tax year. If you work from your San Francisco home on seven or more days in a tax year, you meet that test.
Will a mailbox address keep my home address out of San Francisco's public data?
If you work from home in San Francisco, no. Your home is the location address, and TTX lists location addresses as public. A mailbox in the mailing field keeps your home out of the mailing column only.
Where does San Francisco mail my Business Registration Certificate?
TTX mails the certificate to your business mailing address, which is the only address it uses for documents. If the mailing address isn't up to date, TTX says the certificate can't be printed.
Bottom line
San Francisco business registration asks for a mailing address and a location address, and TTX lists both as public. The mailing address can be any valid mailing address, including a postal box, and your PIN, renewal notices and certificate go there. If you work from home in San Francisco, your home is the location address, and a mailbox can't change that. In our October 17, 2026 count, at least 63% of current locations that started in 2026 used the same address in both fields.
