SimVala

SIP trunk

A SIP trunk for your phone system, paid in crypto

Add one login to 3CX, FreePBX or Asterisk and get 10 lines to phones in 202 countries. No fee per channel and no contract: start with $5.00 of call credit, pay by the second on most routes, from $0.001/min. A number you add rings your PBX and becomes your caller ID. No ID, no email, no card.

Get a trunk login How many channels?

Your phone system

3CX, FreePBX or Asterisk

ext 101ext 102ext 103ext 104

One SIP login

4 of 10 channels in use

No fee per channel. You pay for minutes only.

Calls out

Phones in 202 countries

Calls in

Through a number you add

Illustration. Your login details are on your order page.
channels per login
10channels per login
per channel or per month
$0per channel or per month
lowest rate a minute
$0.001lowest rate a minute
countries you can call
202countries you can call
to start, prepaid
$5.00to start, prepaid

The short version

What a SIP trunk does for a phone system

Your PBX handles the calls inside the office: extensions, ring groups, voicemail, the menu callers hear. A SIP trunk is its road to the outside world. The PBX signs in to a provider with a SIP login, and the provider connects its calls to real phone numbers.

Each call in progress takes one channel. Old phone lines gave you one channel per copper pair; a SIP trunk is just a setting, so the provider decides how many calls a login may carry. Many charge for each one. Ours gives every login 10, free, and charges only for the minutes you use.

It is the same login we sell as a SIP account for phone apps. The difference is only what signs in: one app, or a whole phone system sharing the 10 lines between every desk.

Sizing

How many channels do you need?

The usual advice is one channel for every three or four staff. Your busiest hour tells you more. Enter it, and the calculator works out the lines you need so that callers rarely hit a busy signal.

You need

6 channels

1.5 erlangs of traffic in the busiest hour

One SIP login covers it.

With all 10 channels, fewer than 1 call in 10,000 in that hour would find every line busy.

Worked out with the Erlang B formula, the standard way phone companies size lines. It assumes calls arrive at random and blocked callers do not keep redialling, so leave a channel or two spare if your callers do.

Cost

What a month of calls costs

Trunks are sold two ways: per channel or per minute. Here is how they compare, using ranges from published pricing guides, and what real call patterns cost on ours.

  • Per channel

    About $15 to $30 per channel each month

    Predictable bill; domestic minutes are often included.

    You pay for every line, busy or idle, sized for your busiest hour.

  • Per minute

    About $0.005 to $0.02 a minute to US numbers

    You pay for what you use, which suits most small offices.

    Usually a card, a business account and identity checks first.

  • SimVala

    $0.0018/min to US numbers, 10 channels free

    Per minute, prepaid from $5.00, billed by the second on most routes.

    No contract, no channel fee, paid in crypto with no ID.

Ranges as published by Nextiva and SIP.US, checked 26 October 2026. Per-channel plans often add setup, number and regulatory fees on top.

Home lab or a one-person business

  • 300 min to United States$0.54at $0.0018/min

A month$0.54

Small office in North America

  • 3,000 min to United States$5.40at $0.0018/min
  • 500 min to Canada$0.50at $0.001/min

A month$5.90

Office in Europe

  • 2,000 min to Germany$9.20at $0.0046/min
  • 1,000 min to United Kingdom$2.80at $0.0028/min
  • 500 min to France$2.30at $0.0046/min

A month$14.30

Team that calls family and suppliers abroad

  • 1,000 min to India$2.80at $0.0028/min
  • 1,000 min to Philippines$2.80at $0.0028/min
  • 500 min to Mexico$0.90at $0.0018/min

A month$6.50

Rates for all numbers in each country, from our live rate list. Billing steps differ by route: US calls bill in 6-second steps, and a few countries bill per started minute. No channel fee, no number required, nothing added at the end of the month. Every rate is on the full rate list.

Set it up

Add the trunk to 3CX, FreePBX or Asterisk

The login registers like any SIP trunk: a username, a password and a server. Then two rules finish the job: one sends calls out through it, and one sends your number's calls to the right phones.

Add the trunk in 3CX

Admin console: SIP Trunks, Add SIP Trunk, country Generic, provider Generic SIP Trunk

Field in 3CXWhat to enter
Main Trunk NoYour SimVala number if you have one, otherwise USERNAME
Registrar / Server / GatewaySERVER
Outbound ProxyLeave empty
Type of AuthenticationRegister/Account based
Authentication IDUSERNAME
Authentication PasswordPASSWORD
Number of SIM Calls10

Calls out

  1. 1Outbound Rules, Add: calls to numbers starting with prefix 00.
  2. 2Route 1: this trunk. Strip digits: 2, so the trunk gets the country code first.
  3. 3Narrow the prefix to the countries you call, for example 0044 and 001, rather than all of 00.

Calls in

  1. 1Inbound Rules (DIDs), Add: the number you own, on this trunk.
  2. 2Send it to an extension, a ring group or a digital receptionist.
  3. 3Save, and wait for the trunk to show as registered before testing.

Capitals are placeholders: USERNAME, PASSWORD and SERVER are on your order page, with the transport and port when your login lists them. Menus move a little between versions, but the fields keep these names.

Dial the full international number

Send numbers to the trunk with the country code first, for example 442079460000 for a London number. The dial rules above let your users keep dialling 00 and strip it before the call goes out. In North America, where people dial 011, use the prefix 011 and strip 3 digits instead.

If it registers but there is no audio

Almost always NAT. Turn off SIP ALG on the router, tell the PBX its public address and local networks, and allow its RTP port range through the firewall. The common SIP errors have the rest.

Toll fraud

Lock the PBX before you connect the trunk

A PBX on the internet gets scanned soon after it goes online. When an attacker gets in, they call premium and far-away numbers on your trunk. Five habits stop most of it.

  • Only the countries you call

    Make outbound routes match 0044 or 001, not every number starting 00. Most fraud dials expensive destinations you never use.

  • Long secrets on every extension

    Never the extension number or a short word. Password scanners try those first.

  • Keep the SIP port off the open internet

    Allow only your phones' addresses or a VPN, and turn on the PBX's own firewall or fail2ban.

  • No anonymous calls in

    Turn off guest and anonymous SIP calls, so only your trunk and your phones can reach the dialplan.

  • Keep the balance modest

    Credit is prepaid, so a break-in can spend your balance and nothing more. Top up in amounts you would be fine losing.

Honest fit

Who this trunk suits, and who should look elsewhere

A good fit

  • Small offices and shops with up to a few dozen staff
  • Home labs and hobby PBXs that want real phone numbers
  • Teams that call many countries and want one bill in crypto
  • Anyone who was asked for ID or a company file just to make calls

Look elsewhere if you need

  • Emergency calling with a registered address
  • Hundreds of channels for a call centre
  • Any caller ID you choose, or auto-dialler campaigns
  • Guaranteed carrier attestation (STIR/SHAKEN) on US caller ID

Spam, robocalls and fraud close accounts. The rules are in our Acceptable Use Policy.

Compare

What other trunk providers ask before your first call

From their own pages, checked on 26 October 2026.
ProviderCalls at onceTo get startedPay with
Twilio Elastic SIP TrunkingNo channel limitsAn account and a card; built for developersCard
Telnyx2 until your account is verified, then 10Company details and a payment method for international callsCard
VoIP.msNot statedMinimum deposit; may ask for government IDCard, PayPal, bank wire
Per-channel carriersWhat you pay forA contract or monthly plan, often with setup feesCard or invoice
SimVala10 per login, freeAn account number and $5.00 of creditBitcoin, Monero, USDT and 6 more coins

Get started

Your trunk login, ready for the PBX

Pick your first call credit

The login is free and carries 10 calls at once. Credit pays for minutes on any route, and you can add more from the order page.

  1. 1Make an account: one tap, a number, no email.
  2. 2Top up in crypto, then order the login with your credit.
  3. 3Copy the username, password and server into your PBX.
Add a number for calls in, from $1.99 a month Need more than 10 lines? Order a second login.

SIP trunks, answered

What is a SIP trunk?+

A connection between your own phone system and the phone network, over the internet. Your PBX signs in to a provider with a SIP login, and the provider carries its calls to and from ordinary phone numbers. Each call in progress uses one channel.

Is a SIP trunk different from a SIP account?+

Only in what signs in. A SIP account usually means a login used by one app or desk phone; a SIP trunk is a login used by a whole phone system. Ours is the same login either way, with 10 calls at once, so it works as both.

How many channels do I get, and what do they cost?+

10 calls at the same time on every login, at no extra charge. You pay only for minutes, from your call credit. If you need more than 10, add a second login as another trunk.

Does it work with 3CX, FreePBX and Asterisk?+

Yes. It registers with a username, password and server, which every SIP phone system supports. 3CX adds it as a generic SIP trunk, FreePBX as a chan_pjsip trunk, and Asterisk through pjsip.conf.

How do incoming calls reach my PBX?+

Through a number on your account, from $1.99 a month. Calls to it arrive on the trunk, and an inbound route on your PBX sends them to an extension, a ring group or an IVR.

What caller ID do people see?+

Your number, if you have one on the account. Without one, they see an international number. You cannot set any caller ID you like: showing numbers you do not own is how phone scams work, so we do not allow it.

Is there a contract or a monthly fee?+

No. The login is free, and you start with $5.00 of call credit paid from a crypto balance. There is no contract, no setup fee and no monthly charge for the trunk.

What happens if someone breaks into my PBX?+

They can only spend the credit on your login, because everything is prepaid. That is the main reason to keep the balance modest and to limit outbound routes to the countries you call, as the security section above explains.

Can I make emergency calls on it?+

Do not rely on it for emergency calls. We hold no address for you, so emergency services could not find you. Keep a mobile or a landline for that.

Keep reading

Also useful: Virtual numbers · Call the USA · Call the UK