Do you have any basic questions regarding voice over IP technology or the netvoip offer? Perhaps you'll find the answer in our FAQ section.

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Do you have technical questions about how to operate your netvoip connection? Please check to see if your question appears among the frequently asked questions.

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My Account

You will find information on administering your account and topping up your balance under this category.

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Do you need help setting up your terminal or are other problems arising during the installation? You will find instructions for the most commonly used VoIP devices here.

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Do you want to use netvoip on your computer with a softphone? Here you will find instructions and download links for applications, which we recommend when using netvoip.

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Support form

Were we unable to answer your questions? If you still have open questions or want to report a problem with netvoip, then please click here to fill in the form shown below. We will process your question as quickly as possible.

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What is netvoip?

netvoip combines the latest technologies of Internet telephony with the tried and proven stability of conventional landlines. You decide yourself whether you want to make your phone call using the computer, a VoIP phone, a mobile phone, or your current analogue phone. It doesn't matter how you choose, you will benefit from unbeatable prices and can still use the latest functions and additional services.

What does netvoip cost?

Registering with netvoip is free. You will receive your own landline number that is ready to use immediately. There are no connection fees for using netvoip. You will be billed in centimes per second according to the respective rate for the destination.
Calls from netvoip Prepaid/Talk to netvoip Prepaid/Talk are free.

How do I register?

In order to be able to start using your netvoip account as quickly as possible, you merely have to register an account at the netvoip portal and order the necessary device (phone or adapter) in our shop. The entire process, including shipping the phone, takes about 5 workdays. If you have a software client, you can start making calls only a few minutes after the netvoip registration.

Installing the phone is easy and requires no special computer or network experience as our devices are delivered already preconfigured.

Switch with the normal phone to netvoip

Conventional analogue phones can also be used with netvoip if they are connected to an appropriate adapter. You can choose from several tested devices in our shop.

Is netvoip compatible with any Internet connection?

netvoip lets you make phone calls from any broadband Internet connection that has a minimum bandwidth of 100 kbps upload and download. If you want to make two calls at the same time, a minimum bandwidth of 200 kbit upload and download is required.

netvoip is compatible with all Swiss ADSL connections, cable Internet and all symmetrical standard connections (from 100 kbps).

netvoip is not recommended if you have use an analogue dial-in connection with 56 kbps or an ISDN connection.

How reliable is VoIP via netvoip?

With a stable Internet connection, there are practically no differences in reliability compared to conventional analog and ISDN telephony. Our systems meet the highest demands in terms of stability and quality.

Can I also use other Voice over IP devices?

Yes. netvoip supports all SIP capable devices. Therefore, you can simply use your current Voice over IP phone.
All netvoip configuration details can be seen in your user account.

Can netvoip do everything that my land line can do?

netvoip supports all the common functions of conventional landline connections such as fax, DTMF, CLIP, call waiting, call forwarding, call diversion and much more.

Can I also use my ISDN telephone with netvoip?

If you have a VoIP adapter that supports ISDN telephones, you can use it with netvoip. However, we currently do not have any ISDN compatible hardware in our shop.

Can multiple numbers be used on one netvoip Prepaid account?

Yes, with netvoip Prepaid, you can manage up to 3 connections per account. You can add additional numbers to your account in the connection configuration.

If you require more than 3 numbers, you can switch to the monthly subscription netvoip Talk, which will allow you to add more numbers and will give you a host of additional benefits.

Can I merge numbers from different netvoip Prepaid accounts into one netvoip account?

Yes, with netvoip Prepaid, you can manage up to 3 numbers per account. If you have multiple accounts and want to merge them into one account, please contact our support team.

Fill in the support form at and send us the usernames of the accounts you want to merge. Please note which account you want to use as main account in the future.
You can manage up to 3 numbers per netvoip Prepaid account. If you want to manage more than 3 numbers per account, we recommend you to upgrade your account to a netvoip Talk Account

Can I port my current phone number to netvoip?

Yes, you can port your telephone number to netvoip.

You can find the power of attorney form for number portings here:

Porting form for netvoip Prepaid
Porting form for netvoip Talk

Can I also use netvoip abroad?

If you're planning a trip, your telephone line is coming along. It doesn't matter where you are in the world. You only need to connect your computer or your netvoip adapter to a broadband connection and then you can place a call at local rates to Switzerland. As an alternative, you can also make a call using your smartphone and a VoIP app over a WLAN with netvoip. It goes without saying that you can also receive calls abroad without the caller noticing that you are not in Switzerland, but instead at the other end of the world.

Can I also reach emergency phone numbers and business numbers with netvoip?

Thanks to an in-house solution, you enjoy advantages with netvoip that you will not find with the majority of other providers. Emergency (e.g. 117, 118, 144) as well as business numbers (e.g. 0800, 0848, 0844) can be reached.

I am receiving unwanted calls from a number registered to netvoip

Unfortunately numbers registered to netvoip AG are occasionally abused for outgoing by "spoofing" the number.

The term "Call ID Spoofing" refers to the method by which outgoing calls can be performed, while hiding the actual calling number and displaying a different spoofed number. Sometimes these spoofed numbers are assigned to one of our partners or a customer of Netstream. Most of these calls originate from foreign countries, and aren't originating from, or being routed through Netstream AG. These calls are routed through different systems, in some cases through Telephone/PBX systems of private or business customers.

If you are repeatedly receiving spoofed calls, you may file a complaint with the local police authority or local civil court. A criminal complaint can be lodged at any local police station.


Calls to international Premium Rate Service (PRS) numbers

International Premium Rate Service (PRS) numbers, may not be dialled with netvoip for technical reasons.

Personalized voicemail message

If you set up your number on multiple devices it you would need to confirm your phone number before entering the password.

Dial * 98 to be forwarded to the voicemail menu. If you access the voicemail menu, you will first be asked for your password. The password is specified in the activation of the voice box on Now navigate the interactive voice menu using the following key sequence to personalize your voicemail greeting: 3 -> 3 -> 2 -> 2.

You may also provide your self-recorded .mp3 file as a custom announcement. Contact our support team at with the .mp3 file attached. We also need your username and telephone number for which the voicemail greeting is to be uploaded. Make sure that prepaid Plus is enabled for your account.

Default Voicemail announcement

If you set up your number on multiple devices you would need to confirm your phone number before entering your password.

Dial * 98 to access the voicemail menu. Once in, you will first be asked for your password. The password is specified at the configuration of the voice box on Now navigate the menu using the following key sequence to set your default voicemail announcement: 3 -> 3 -> 2 -> 1.

The phone does not ring on incoming calls.

If outgoing calls work perfectly but there is no ringtone with incoming calls (but the ringing tone can be heard on the other end), the problem may have to do with the firewall:
It often helps to deactivate SIP-ALG on the firewall. Tips and tricks for some firewalls in combination with SIP can be found at:

Calls are cut off after a short amount of time.

A firewall may take the many UDP packages sent via voip as a flooding attack and as a result shut down the connection. Consequently, the talks get interrupted. Switch off recognition of flooding attacks in your firewall or increase the tolerance threshold. This should prevent this problem from happening.

Fax over IP

What do you need ?
- a netvoip- account
- netvoip Prepaid Plus
How do I proceed?
Faxes can only be received through your faxbox. You therefore need to activate your faxbox in your number's call settings. Faxes will then be forwarded to the e-mail address saved under your faxbox.

The number you have called is currently not in service

You may hear an announcement when calling your netvoip number saying that the number is unavailable. There may be several reasons for this:

Recently registered:

In the case of recently registered phone numbers, it may take up to an hour to update all systems and set up the account.

You haven't been able to succesfully configure netvoip yet:

Please check the router, firewall and end device configuration. You can find relevant information on configuring various devices under our Support page.
You were able to connect to netvoip once already:

Please check whether your netvoip adapter or end device is connected correctly and whether they are powered on. A restart may be worthwhile, particularly for devices with integrated routers.

DTMF doesn't function

With outgoing calls, it is possible that the DTMF tones are not completely transmitted, which means that the commands that are passed on to the recipient via the buttons may not be fully received. Please check the configuration of your telephone and use the RFC2833 standard for DTMF.

What does SIP mean?

SIP stands for Session Inititiation Protocol and refers to the most used call signaling protocol.

Can I listen to my voicebox over the phone?

You can access your voicemail directly from your phone. Dial *98 to be forwarded to the voicemail menu. Once you're in the voicemail menu, you will first be asked for your password. The password is specified during the activation of the voice box on

If you set up your number on multiple devices you will need to confirm your phone number before entering your password.

Which ports are used for netvoip?

SIP: 5060
RTP: 35000-65000

Which codecs are supported by netvoip?

The following codecs are supported by netvoip for landline and mobile calls: G.711a-law, G.711 u-law

What is HD Voice?

HD Voice enables high definition voice quality thanks to the standards based g.722 voice codec.

This codec can be used in phone calls between netvoip customers. For calls to external networks it is not possible to use this codec, since these calls are routed through the fixed line telephony network. In those cases the standard codec g.711 is used.

The selection of the g.722 codec is prompted by the hardware phone or software client of the person making a call. Depending on your device or software it is possible to choose your preferred codec, along with secondary codecs if calls with the preferred choice are not possible. For help with the configuration of your codec preference we advise you to consult the support of your hardware or software vendor.

Is my VoIP connection secure?

Your passwords are not transmitted in clear text but as an encrypted hash in the signaling data for the voice calls. Although calls via SIP/RTP are transmitted unencrypted, because of the different paths individual voice packages take it is unlikely that a conversation can be listened to remotely. Encrypted voice calls are possible through TLS with our Lync products like Hosted Lync and Lync Connect.

How can I block incoming calls?

It is possible to block individual numbers or entire number ranges using a wild card symbol. This service is only available for netvoip Prepaid Plus/Talk clients. Numbers added to the blacklist are no longer able to reach you. Swiss numbers can be entered using the national number format, for example 044xxx. International numbers must be entered in the following format: 0049xxx. Anonymous calls cannot be blocked.

You may also block entire ranges by using the star symbol ( * ). For example the entry 044xxx* would block all calls from phone numbers starting with 044xxx.

It is also possible add numbers to the blacklist from the "All calls" view by clicking on the Telephone icon next to the call details. The number will be automatically added to the blacklist.

How many numbers can be added to the blacklist?

The blacklist is limited to 30 entries.

What countries are included in the call barring list "calls outside of Europe"?

Only calls to the following countries are possible if that call barring list is selected: Andorra, Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Gibraltar, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Monaco, Netherlands, Norway, Poland, Portugal, Romania, San Marino, Slovakia, Slovenia, Spain, Sweden, Switzerland, United Kingdom, Vatican City.

If the option "Calls abroad" is activated, only calls to Swiss numbers are possible.

How can I block promotional calls from call centers?

Since the amendment of the Telecommunications Act on the 01.01.2021, blocking these advertising calls has been a major issue. As a telecommunications service provider, we are obliged to operate a technically suitable solution to prevent these calls. However, currently each provider can decide independently on what this solution looks like. Many of the large providers are currently working with dynamic block lists that are filled with new phone numbers based on evaluations of the call statistics. In principle, this is a rational approach, but there are various problems:

1. There are different providers with these block lists. As a result, nobody can tell exactly which numbers will be blocked and which won`t. So nobody is really responsible.

2. If you end up on these block lists with your own number, there are no efficient ways to get off the list again. We already had various major customers (including banks, insurance companies, etc.) whose main number could no longer be reached by Swisscom and Co. The problem can only be resolved after a few weeks.

3. Call centers are constantly using new number ranges. As a result, the blocklists actually only block reactively. Often numbers are no longer in use when they land on the block lists. Our strategy in this regard is, that we currently only prevent very clear spamming. We currently do not want to use a list form a third-party provider because we generally assume that our customers (especially business customers) would rather receive one call too much than one call less. If the load caused by the calls is so great, then replacing your phone number may help. We hope that in the coming months and years there will be more efforts on the market to solve the problem globally.

My Account

Can I control multiple devices using one telephone number?

Yes, this is possible. You can manage up to 5 devices for each number.
You can do this via Account > Configuration > Devices.
Please note, however that you will need to reconfigure your existing telephone if you want to use more than one device.

Can I access my Voicebox with my phone?

Yes, you can access your voicebox by dialling *98. Incoming voice messages will also be sent via e-mail in MP3 format.

If you use a Fritzbox, you can access your voicebox by dialing *#*98 .

How can I top up my netvoip prepaid credit?

You can top up your netvoip prepaid account easily and quickly using the following payment methods: Postfinance E-Finance, PayPal, TWINT, Credit Card.

If you are unable to top up the credit via the payment methods, you can transfer the credit to our Bank account. In order to allocate the bank transfer, please provide us with the following details via the netvoip Support form: name of bank account holder, value date, amount, netvoip prepaid user name. The payment will then be credited to the netvoip Prepaid account within 5 working days.

Bank account netvoip AG, Alpenstrasse 1, CH-8803 Rüschlikon:
Raiffeisen Schweiz Genossenschaft, CH-9001 St. Gallen
Konto: 01-76492-4
IBAN: CH15 8080 8003 5471 3676 8

Can I also be billed on a monthly basis?

Yes. Besides our prepaid solution, you can also find VoIP offers that you can pay conveniently with a monthly invoice at

Why is older call information no longer visible?

For data protection reasons, all call information is deleted after 6 months.

Mobile phone provider incorrectly recognised

I just called on my Sunrise mobile phone, which has a 078 number. However, it is identified as a Salt mobile phone on the call register and billed accordingly. Why is that?
For technical reasons we, as many other providers too, can identify the mobile service provider only on the basis of the prefix 076, 078 or 079. If you have an 076 number from Sunrise and switch later to another provider, you will still be billed at a Sunrise mobile rate."

How long does it take for a PostFinance (E-Finance) payment until the amount is credited to the netvoip-account?

After making a payment through PostFinance (E-Finance), the Post needs about three days to process the payment and transfer it to us.

Help for PayPal top-ups

Ensuring the security and protection of your user data on netvoip is very important to us. To ensure that payment can be made via PayPal, you need to meet the following conditions:

1. E-mail validation modification

Please make sure that you use the same e-mail address for your PayPal account as you do for netvoip.

2. Validated Swiss PayPal account prerequisite

You have a Swiss PayPal account that has already been validated.

You can find more information at here.

Why does PayPal top-up only work with a credit card?

The requirement for a PayPal top-up is a verified Swiss PayPal account. When you first sign up for a PayPal account, you have an initial sending limit. After the sending limit is reached, or in certain cases when using your PayPal account, you will be requested to link and confirm your credit card or become a verified PayPal member before you can submit any further payments with PayPal. This verification of your PayPal account is only possible with a credit card.

You can find detailed information on how to verify your PayPal account at here.

If you have only been topping up your PayPal balance via bank transfer, we recommend you choose a different payment method for netvoip. You have the following options for payment:

- Postfinance E-Finance (Postcard)

- Twint

Is there a limitation when charging your account by credit card or Paypal?

The limit per transaction is CHF 999.-


Configuring VoIP devices

If you order your VoIP adapter or your VoIP phone directly from us, you will receive the device already configured. You simply have to connect it according to the enclosed guide.

If you already have a a VoIP device or a Softclient you can use it with netvoip. To configure it please proceed as follows:

Open up the configuration menu of the device. Please note that the exact layout of the configuration screen is device specific - please consult the device manual for details on how to configure it.

Normally only the following configuration parameters need to be adjusted:
Telefone number (Username), PIN (Password) and SIP Server (Gateway/Registration Server). ""Register Expiration Timeout"" should be set to 2 minutes. You will find the necessary information for your account in the ""Account"" category of netvoip under ""Devices"".
Here are instructions on how to find these parameters in the netvoip login:

Setting up a Fritz!Box for netvoip

Instructions for installing and configuring your Fritz! Box for netvoip can be found under the following link:

AVM Fritz!Box ATA

If incoming calls suddenly no longer work with a Fritzbox, the reason might be that the "Keep port forwarding of the Internet router active for Internet calling" option under the advanced settings is not enabled. Enable it and select 1 minute.

Setting up Gigaset for netvoip

Instructions for installing and configuring Gigaset for netvoip can be found under the following link:

Setting up Snom for netvoip

Instructions for installing and configuring your Snom for netvoip can be found under the following link:

Setting up Yealink for netvoip

Instructions for installing and configuring Yealink for netvoip can be found under the following link:

Setting up Asterisk for netvoip

Instructions for installing and configuring Asterisk for netvoip can be found under the following link:


Make calls using IOS


With the Acrobits Softphone Client (app) you can call and be reachable via 3G / 4G / 5G, EDGE or a public or private WIFI with your netvoip account.
You can find the application in the Apple App Store with this link:

You can find registration instructions here:

Caution: If calls are made or received via mobile data, connection costs may arise on the part of your mobile network operator. These costs are not billed to your netvoip account.


Make calls with the Zoiper app with your netvoip account from an IOS phone/pad.

You can download the app here:

You can find registration instructions here

Make phone calls from your computer

Call easily and conveniently with the Zoiper softphone from your desktop computer.

You can download the desktop software here::

Instructions for setting up can be found here: here

Make calls using Android


With the Acrobits Softphone Client (app) you can call and be reachable via 3G / 4G / 5G, EDGE or a public or private WIFI with your netvoip account.
You can find the application in the Google Play Store with this link

You can find registration instructions here:

Caution: If calls are made or received via mobile data, connection costs may arise on the part of your mobile network operator. These costs are not billed to your netvoip account.


Make calls with the Zoiper app with your netvoip account from an Android phone/pad.

You can download the app here:

You can find registration instructions here

Support form

Support form

We update our platform regularly. To stay up to date with the scheduled maintenance windows, check our Service Status Page.

If you are having problems with netvoip, please fill out the form below. We will process your enquiry as soon as possible.

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