How to Add Multiple SIP Accounts to a Softphone

Adding a second SIP account to SIPdia works the same way as adding the first: open the Account page, fill in the server and credentials, and register. On the Mac, click Add Account; on iPhone and iPad, tap Add at the top of the Account tab. Every account registers at the same time, each one keeps its own feature codes and forwarding, and the From picker on the dialpad decides which account an outgoing call uses. The free plan registers one account; SIPdia Premium removes that limit.

This tutorial shows the steps on both platforms, explains how calls are tied to accounts, and then looks at why people run several SIP accounts in one app in the first place.

Before you start

Each SIP account is an independent registration, as defined in RFC 3261. For every account you want to add you need:

• the server address (host, optionally :port),
• the transport (UDP, TCP or TLS),
• the username (the extension number on a PBX),
• the password,
• and, if the provider lists them separately, an auth username, a domain or an outbound proxy.

The first account you created is the default account. That is the one that registers on the free plan.

Add an account on macOS

1. Open SIPdia and click Account in the sidebar.
2. Click Add Account.
3. Enter Server, Transport, Username and Password. Set a Display name if you want this account to show a different name to the people you call.
4. Open Advanced if this account needs Domain, Outbound proxy, Auth username, a STUN server, ICE or a different Encrypt audio setting. Each account has its own values here, so a PBX extension over a VPN and a provider account over the internet can use different NAT and encryption settings.
5. Click Save and Register. The dot for this account turns green when the server accepts the registration.
6. Repeat for every further account.

Add an account on iPhone and iPad

1. Open SIPdia and go to the Account tab.
2. Tap Add at the top of the tab.
3. Enter Server, Transport, Username and Password, and any Advanced fields the account needs.
4. Tap Add and Register. The dot turns green once the account is registered.
5. Repeat for every further account.

Choose the account for an outgoing call

Once more than one account is registered, a From picker appears on the dialpad on both platforms. Select the account before you dial. The call leaves through that account, so the server, the dial plan and the caller ID that the called party sees all belong to the account you picked. If you call a colleague's extension from your provider account by mistake, the provider will try to route a short internal number to the public network and the call will fail, so check the picker when the number looks unusual.

Know which account a call came in on

Incoming calls show which account they arrived on, both in the incoming-call window (Mac) or the system call screen (iPhone), and later in Recents. This matters when two accounts share a device: a call to your office extension and a call to your personal provider number can be answered differently, and the Recents list tells you later which line was busy.

Feature codes and forwarding per account

Feature codes are star codes that a PBX such as Issabel or FreePBX understands, for example *72 followed by a number to forward all calls. They belong to the PBX, not to the app, so SIPdia keeps a separate set of codes for every account under Settings > Feature Codes. The defaults are the common Asterisk-style codes:

Action	On	Off
Forward all calls	*72 + number	*73
Forward when busy	*90 + number	*91
Forward when not answered	*52 + number	*53
Do Not Disturb	*78	*79
Voicemail	*97

Forwarding and Do Not Disturb (Premium) are set per account on the Forwarding page or tab. SIPdia dials the code through that account, the PBX confirms, and the setting lives on the PBX, so it keeps working when the app is closed. Most SIP providers have no feature codes. For a provider account, clear the codes and set the voicemail code to the provider's voicemail number; forwarding for that account is then configured in the provider's portal instead.

Why run several SIP accounts in one softphone?

Multi-account support is common in SIP clients because a SIP account is just a registration against one server. Nothing in the protocol stops a client from holding several registrations at once. Typical reasons:

• Work and personal lines on one device. An office PBX extension and a personal provider account, each with its own number, voicemail and history, without carrying two phones.
• Several offices or clients. Consultants and support staff often need an extension on more than one customer PBX. Each registration stays separate, and the From picker chooses which company the call comes from.
• Local numbers in several countries. Providers sell numbers in different countries. Registering one account per number lets you call out with a local caller ID for each market.
• Separating billing or departments. A sales line and a support line on separate accounts keep call records apart.
• A backup route. A second provider account gives you a way to call out when the first provider or PBX is unreachable.

Two practical notes. Every registration refreshes itself on a timer and keeps a small amount of network traffic going, so on a laptop or phone running on battery, add only the accounts you use. And when two accounts point at the same server with the same username, the server treats them as one contact, so give each account its own credentials.

Next steps

• The multiple SIP accounts feature page summarises what works per account on each platform.
• New to SIPdia? Start with How to Set Up a SIP Softphone on macOS with SIPdia or the iPhone and iPad version.
• Adding a provider account next to a PBX extension? SIP Registration: PBX Extension vs Provider Account explains the differences in credentials, NAT and feature codes.