Quick answer: Add a second VoIP Office Phone entry under the second number's detail page in Organization Settings → VoIP, then register it as a second account on the handset. Each entry needs its own SIP username, SIP password, and Transfer Number.
Who this is for: Organization Settings admins who have more than one VoIP phone number and want one physical desk phone to answer calls for two of them.
Before you start, you'll need:
Admin access to Organization Settings
Both phone numbers already provisioned for your organization
A Yealink desk phone already registered for the first number
A Transfer Number that is not already in use anywhere in your organization
❗ Transfer Numbers must be unique across your entire organization — not just within one phone number. Barti does not check for duplicates, and the settings screen only shows the handsets for the phone number you are currently viewing, so a Transfer Number already in use on a different number will not be visible to you. If two handsets share a Transfer Number, dialing that extension rings both of them at once. Keep your own list of assigned extensions and check it before adding a phone.
These steps apply to the Yealink T54W, T74W, and T85W.
How it works
Each VoIP Office Phone entry in Barti is a set of SIP credentials tied to one phone number. A physical handset can hold more than one account, so to answer two numbers on one handset you create a second entry in Barti and register it as a second account on the phone.
The entry is assigned to a phone number by which number's detail page you create it from — there is no phone number field in the form. Creating the entry from the wrong page assigns it to the wrong number, and an entry cannot be moved to a different number afterward.
Your organization has a single SIP Address, shared by every phone number. Both accounts on the handset use the same SIP Address, and differ only by SIP username and password.
Step 1 — Add a second phone entry in Barti
Go to Organization Settings → VoIP.
Click the edit icon on the card for the second phone number — the one the handset does not answer yet. Confirm you are on the correct number's detail page before continuing.
Scroll to the VoIP Office Phones section.
Click Add Phone.
Enter a Phone Display Name that identifies both the handset and the line, for example "Front Desk — Billing Line". This makes the two entries easy to tell apart.
Enter a SIP Username. It must be different from every other SIP username in your organization. Only letters, numbers, and underscores are accepted.
Enter a SIP Password (12 chars min). Use at least 12 characters with one uppercase letter, one lowercase letter, and one number. Use a different password from the handset's first account.
Enter a Transfer Number between 1 and 99. This is the extension staff dial to reach this line on this handset. It must not already be assigned to any other phone in your organization.
Click Add.
The new entry appears in the VoIP Office Phones list for this phone number. Note the SIP Address shown in this section — you will need it in Step 2, along with the username and password you just created.
Step 2 — Register the second account on the handset
Find the handset's IP address by pressing OK on the phone.
On a computer on the same network, enter that IP address in a browser and log into the phone's web interface.
Go to Account → Register.
In the Account dropdown at the top of the page, select Account 2. Leave Account 1 alone — it holds the first number's registration.
Set Line Active to On.
Enter a label in both the Label and Display Name fields. This is what appears on the phone's screen for this line, so name it for the second number, for example "Billing".
Copy and paste the new SIP Username from Barti into both the Register Name and Username fields.
Copy and paste the new SIP Password from Barti into the Password field.
Copy and paste the SIP Address from Barti into SIP Server 1 → Server Host. This is the same SIP Address used by Account 1.
Click Confirm.
Important: Copy and paste all credentials directly from Barti rather than typing them. Extra spaces and typos are the most common cause of registration failures.
What you'll see when it works
Registration Status for Account 2 shows Registered, and the label you entered appears as a second line on the phone's screen. The handset now rings for calls to either number, and the screen shows which line an incoming call arrived on.
Outbound calls use whichever line you select before dialing. Each line carries its own number as the caller ID.
In Barti, the new entry is listed under the second phone number in Organization Settings → VoIP, with its own Transfer Number.
Troubleshooting
I dialed the transfer extension and two phones rang at once.
Two phone entries share the same Transfer Number. Barti does not prevent this, and because the extension lookup covers your whole organization, the conflict can be with a handset on a different phone number. Open each phone number's detail page in turn, note every Transfer Number in use, and edit one of the duplicates to a free value.
I added the phone under the wrong phone number. Can I move it?
No. A phone entry cannot be reassigned to a different phone number after it is created. Delete the entry from the three-dot menu, then create a new one from the correct number's detail page. You will need to re-register that account on the handset with the new credentials.
Adding the phone failed with "Failed to create phone".
This usually means the SIP username is already taken. SIP usernames must be unique across your entire organization, including usernames on other phone numbers and on phones you have since stopped using. Try a more specific username, such as one that includes both the line and the handset.
The second account won't register.
Confirm you pasted the credentials rather than typing them, and check for leading or trailing spaces. Confirm the Server Host matches the SIP Address shown in Barti exactly. Confirm you edited Account 2 and not Account 1 — overwriting Account 1 unregisters the first number.
Can one handset answer more than two numbers?
Yes. Repeat both steps for each additional number, using the next available account slot on the handset and a new phone entry under that number in Barti. Each account needs its own SIP username, password, and Transfer Number.
Do both lines share a voicemail greeting and call recording settings?
No. Voicemail greeting and call recording are configured per phone number, so each line follows the settings of the number it belongs to, regardless of sharing a handset.
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