Some of these settings affect every user at once. Where a task changes the whole database, test it on a duplicate first; the duplicate-database task below shows how.
1. How to install one Odoo app
Install an app you can name. Do not install a module file from a stranger onto a database that already has real orders.
Back up first
If this database has data you need, take a backup before you install. A module can add menus you did not expect, and a backup is the way back.
Find the app
Open Apps and search for the app name. On a server you run yourself, update the apps list first if the app should be there and is missing.
Install and open it
Click Install and wait until it finishes. Open the new app from the menu. If the install errors, read the message and do not click Install again until you know why.
Leave unknown files alone
Do not upload a zip or a module you cannot rebuild from a source you trust. Test that on a copy of the database, not on the live one.
Common questions
Will Install delete my data?
A normal official app install adds features. It should not be how you remove data. Still back up first when the database matters.
What if the button says Upgrade?
The app is already installed. Upgrade only when you mean to update that module.
Can I uninstall if I dislike it?
You can try, but uninstalling an app that already has records is riskier than installing it. Decide before you enter real data.
Menu labels vary with your Odoo version, installed apps, and permissions. Compare them with the Odoo 19 applications documentation when a label differs.
2. How to activate Odoo developer mode
Developer mode reveals advanced tools. It does not change records until someone uses those tools.
Turn it on from Settings
Open the Settings app, scroll to Developer Tools, and click Activate the developer mode. Odoo then shows Deactivate the developer mode.
Expected: a bug icon appears, and Settings shows the technical menu for a database administrator.
Turn it on from the address bar
Add ?debug=1 to the end of the database URL, for example https://example.odoo.com/odoo?debug=1. Use ?debug=0 to turn it off.
Use ?debug=assets only when you are debugging JavaScript. You can also open the command palette with Ctrl+K or Cmd+K and type debug.
Use the technical menu carefully
The bug icon opens tools for the screen you are on, such as fields, filters, and actions. The technical menu in Settings holds database structure, security, and actions.
Do not edit a view, a group, or an automated action unless you know the effect and can restore it. Odoo warns that some of these tools are advanced.
Turn it off when you are finished
Click Deactivate the developer mode, or load the page with ?debug=0. Leave it off for people who only record daily work.
Developer mode applies to the browser session. It does not give a user access rights they do not already have.
Common questions
Is developer mode the same as debug mode?
Yes. Odoo documents developer mode as debug mode. Both names refer to the same switch.
Does turning it on change my data?
No. Activation only reveals tools. Records change when you use one of those tools.
Can every user activate it?
A user can activate it for their own session when Settings shows Developer Tools. It does not add access rights.
Odoo documents this as developer mode, also called debug mode, in the Odoo 19 developer mode page.
3. How to add a language in Odoo
Activating a language loads its translations. A user still has to choose it. The website language is a second switch.
Add the language
Open Settings and click Add Languages in the Languages section. Select one language and click Add. You can also open your profile and use the globe beside Language.
Switch one user
On your own profile, choose Language. For someone else, open Settings → Manage Users, select that user, and set Language on the Preferences tab. Reload. Menus for that user should change. Other users stay as they were.
Set the website separately
Go to Website → Configuration → Settings. Install the language if it is not listed, select it under Languages, and save. A user’s backend language does not add that language to the public site.
Expect gaps
Some of your own field labels and product names stay in the language you typed. Translate those records. Do not assume every string is covered.
Common questions
Does this translate my product names?
No. You entered those. Translate the product if the shop needs it.
Can each user have a language?
Yes. The preference is per user.
What if the language is missing from the list?
Add it from Settings first. A user can only choose a language that has already been added.
Odoo documents adding a language in the Odoo 19 languages page, and adding it to a website in the website translations page.
4. How to add your logo to Odoo invoices
The document layout puts the same logo, address, and footer on the company’s external reports. Change it once, then print one invoice to prove it.
Open the document layout
In Settings, find the Companies section and click Configure Document Layout. The preview on the right shows the header before you rely on it.
These settings belong to the active company and apply to its reports, including quotations and invoices.
Set the logo, address, and paper size
Edit the company logo. Check the address, tagline, footer, and paper format. Odoo offers A4 and US Letter here. Saving the logo also updates the company record.
Use the footer for the legal line you must show, such as a registration number, only when that number is already on the company record or your accountant has confirmed it.
Print one draft invoice
Open a draft customer invoice and print or download the PDF. Confirm the logo, company name, and address on the file, not only on the screen preview.
If a self-hosted server prints a blank header, the PDF engine may be missing. The Ubuntu install guide names the documented package. Fix that before you redesign the report.
Change the company you are editing
Select the company in the company selector before you open the layout. A logo saved for one company does not replace the logo of another company in the same database.
Common questions
Will quotations use the same logo?
Yes. This layout is the company default for external reports, not a change to one invoice.
Can each company have its own logo?
Yes. Select the company first. The layout is company-specific.
The preview shows the logo, but the PDF does not. What should I check?
Save the layout and print again. On your own server, compare the result with the packaged install notes before editing the report design.
Odoo documents Configure Document Layout in the Odoo 19 PDF reports page.
5. How to add a second company in Odoo
A second company is a separate legal entity in the same database. Decide that before you create branches or share products.
Choose a company or a branch
Use a company for a separate legal entity. Use a branch for an office or department under a parent company you have already created. Odoo says a parent cannot later be converted into a branch.
Create the parent first. Independent subsidiaries are additional companies, not branches.
Create the company record
Go to Settings → Users & Companies → Companies and click New. You can also open Settings, find the Companies section, and click Manage Companies.
Enter the name, address, currency, and tax ID your accountant expects, then save. General fields can vary with the fiscal localization.
Choose who can open it
Give each user only the companies they should see. Click the company selector at the top right, tick the companies to show, and click a name to make it the active company. The highlighted name is the active one.
Odoo 19 documents that enabling multi-company on an Online Standard plan can move that database to the Custom plan. Read the current pricing page before you enable it. The same page says this does not apply to the One-App Free plan.
See what is shared
Quotations, invoices, and vendor bills stay with the company stored on the document. Open that company to see them. New products and contacts are shared until you set the Company field.
A product can keep one sales price and still have a different cost in each company. Leave inter-company transactions off until the fiscal positions for both companies are set.
Common questions
Should a new shop be a company or a branch?
Use a company for a separate legal entity. Use a branch only under a parent company you have already created.
Will the second company see the first company’s invoices?
No. Open the company stored on the invoice. Those documents stay with that company.
Does a second company change the Odoo subscription?
Odoo 19 documents an upsell from the Online Standard plan to the Custom plan when multi-company is enabled. Check the current pricing page before you do it.
Odoo documents companies, the company selector, and the Standard-plan change in the Odoo 19 multi-company page.
6. How to duplicate an Odoo database for a test
A duplicate is a test copy. It must not send customer email or take live payments.
Open the database manager
On a server you administer, open the database manager. This is not the same screen as a user’s login. It asks for the master password, which is the server credential described in the password guide.
Duplicate and rename
Choose the database and Duplicate. Give the copy a name that cannot be confused with the live database.
Stop outgoing mail
A duplicate is a neutralized database. Neutralization turns off outgoing email, payment providers, and other live actions, and shows a red banner. Confirm that banner before anyone tests. If you copied the database another way and there is no banner, disable outgoing mail on the copy first.
Do not publish the copy
Keep the copy off a public address, or restrict who can open it. A copy still contains customer data. Delete the copy when the test is finished.
Common questions
Is the master password my login?
No. It is the database-manager credential. Resetting a user password does not set it.
Will the copy affect the live database?
Not if you opened the copy. Check the database name in the URL before you change anything.
Should I test on the live database instead?
No, when the test can send mail, post invoices, or install an app.
Odoo documents what a duplicate turns off in the Odoo 19 neutralized database page.
7. How to turn on Odoo two-factor authentication
Two-factor authentication asks for a second code after the password. Turn it on for your own user and prove you can still sign in.
Open My Preferences
Click your profile avatar at the top right and choose My Preferences. Open the Security tab and click Enable 2FA.
Confirm a current code
Enter your password when Odoo asks, then scan the QR code with an authenticator app. If you cannot scan it, use the Cannot scan it? link. Enter the verification code and click Enable Two-Factor Authentication. Do not store a screenshot of the QR code in a chat.
Know how a lost phone is recovered
Odoo 19 does not give you backup codes on this screen. If the authenticator is lost, an administrator has to turn 2FA off on that user before the person can sign in. Do that only after you know the request is genuine.
Sign in again
Sign out. Sign in with the password, then enter a new authenticator code on the two-factor page. Keep the current session open until that second sign-in works.
Common questions
Does this change my password?
No. You still use the password, then the code.
Should an administrator turn it on for everyone remotely?
Each person should enroll and confirm a code. To require it for everyone, an administrator turns on Enforce two-factor authentication under Settings, in Permissions, for employees only or for all users.
What if the phone is lost?
An administrator turns 2FA off for that user. The person then signs in with the password and enrolls a new authenticator. Reset the password only if the password itself is compromised.
Odoo documents these steps in the Odoo 19 two-factor authentication page. Some localizations do not allow 2FA to be turned off.
8. Related guides and next steps
Sample names and amounts are illustrative. They are not a client result, a price, or legal or tax advice. Menus can differ between versions and installed apps.
Continue learning
Describe your business, the system you use now, and what has to change. See our Odoo implementation service or contact OdooMatrix.