Office Phone Test


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Office telephones

Our test winner is the Yealink VP59 SIP Video Phone: The device has a high-resolution touch display, video telephony and convinces with intuitive operation. Our favourite with the test mark 9.3/10!

We have tested 6 office phones and paid special attention to the operation, setup and telephony.

The office telephone is indispensable for every workplace. By switching to IP telephony, the newer models have numerous functions that make everyday office life much easier.

We test independently. uses affiliate links. For a purchase via a link marked with a or our price comparison, we may receive a small commission.

last modified: 28.02.2020, 14:01
Winner Best price winner
Our winner: Yealink VP59 SIP Videophone Gigaset PRO Maxwell 10S Review Yealink SIP T5 Series T53 Review Tiptel Htek UC924E VoIP-Phone Review Snom Global Desk Telephone D785 Review Snom D735 Desk phone Review

Yealink VP59 SIP Videophone

Gigaset PRO Maxwell 10S

Yealink SIP T5 Series T53

Tiptel Htek UC924E VoIP-Phone

Snom Global Desk Telephone D785

Snom D735 Desk phone

Test seal: Yealink VP59 SIP Videophone, Rating 1.5
Test seal: Gigaset PRO Maxwell 10S, Rating 1.6
Test seal: Yealink SIP T5 Series T53, Rating 2.4
Test seal: Tiptel Htek UC924E VoIP-Phone, Rating 2.4
Test seal: Snom Global Desk Telephone D785, Rating 2.4
Test seal: Snom D735 Desk phone, Rating 2.7
  • Large touch display with good resolution
  • Good hearing and speech quality
  • Intuitive operation
  • Video telephony
  • Google Play Store
  • Large display
  • Good hearing and speech quality
  • Video telephony
  • Good hearing and speech quality
  • Intuitive operation
  • Timeless design
  • Simple operation
  • Good sound
  • Simple design
  • Simple operation
  • Good sound
  • Pleasant loudspeaker
  • Simple design
  • Simple operation
  • Good sound
  • Pleasant loudspeaker
  • Relatively quiet loudspeaker
  • No Google Play Store
  • Unclear instructions
  • Hardly any additional functions
  • Speakers relatively quiet
  • No video telephony
  • Interlocutor hears himself on the loudspeaker
  • Few additional functions
  • No video telephony
  • Problems with the setup
  • Hardly any additional functions
  • No video telephony
  • Problems with the setup
  • Hardly any additional functions
  • No video telephony

A smart phone with many functions. Perfect for any office and for all tasks.

With access to the Google Play Store, the phone is feature-rich and ideal for any office job.

A classic office telephone, which however has hardly any additional functions. But it is well suited for pure telephony.

A good and practical telephone for any office that fully serves its purpose.

A good and simple phone. Ideal for any office that does not require additional functions.

A simple phone for easy use, whose good sound is convincing.

Range of functions
Quality impression Very Good Good Good Good Good Good
Handling Navigation keys, numeric keypad and function keys Touchscreen Navigation keys, numeric keypad and function keys Navigation keys, numeric keypad and function keys Navigation keys, numeric keypad and function keys Navigation keys, numeric keypad and function keys
Width 27 cm 33,6 cm 21 cm 22,5 cm 21 cm 18,5 cm
Height 22,5 - 28 cm 25 cm 17 cm 19,5 cm 15,5 cm 15 cm
Depth 22 cm 11,5 cm 17 cm 16,5 cm 20,5 cm 20,5 cm
Weight 1,6 kg 1,03 kg 0,9 kg 1,025 kg 0,95 kg 0,83 kg
Scope of delivery Phone with display, camera, handset, LAN cable, quick start guide Gigaset Tablet, DECT - handset, metal stand, network cable, power supply unit, manual, safety instructions Phone with display, handset, LAN cable, quick start guide Phone with display, handset, LAN cable, quick start guide Phone with display, handset, LAN cable, quick start guide Phone with display, handset, LAN cable, quick start guide
Display size 8 inches 10 inches 3,7 Inches 3,5 Inches 4,3 Inches 2,8 Inches
Loudspeaker function
Video calls
Internal memory 12 GB, up to 1000 contact entries 10,51 GB - - - -
Memory expansion ✔ - via USB ✔ - via SD card - - -
Ports 2x RJ-10, 2x LAN, HDMI, USB 2.0, USB for the camera, WLAN, Bluetooth 3x LAN, 2x USB, 2x RJ-10, W-Lan 2x RJ-10, 2x LAN, USB 2.0, 2x RJ-10, 2x LAN, RJ45 WLAN, Bluetooth 2x RJ-10, 1x RJ12, 2x lan, USB 2.0 2x RJ-10, 1x RJ12, 2x lan, USB 2.0,
Packaging Plain cardboard Cardboard Plain cardboard Cardboard Cardboard Cardboard
Additional warranty - - - - - -
Quality of instructions Satisfactory, illustrated, short Unsatisfactory Satisfactory, illustrated, short Good Satisfactory, illustrated, short Satisfactory, illustrated, short
Manual language GB GB GB GER GER, GB, FR, IT, ES GER, GB, FR, IT, ES
- - - - - -
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*All prices include VAT (if applicable, extra charge for delivery. Check the particular online shop to find information about the availability. Changes of indicated prices since the last update remain reserved.

Tested products

1st place: Yealink VP59 SIP Videophone

Test seal: Yealink VP59 SIP Videophone, Rating good

The Yealink VP59 SIP Videophone is a versatile office phone and can convince with its good sound quality as well as workmanship and many functions on Android basis. Unfortunately, you can't download any other apps and therefore can't use the full extent of Android.

read review
Gigaset PRO Maxwell 10S - thumbnail Test seal: Gigaset PRO Maxwell 10S, Rating good

2nd place: Gigaset PRO Maxwell 10S

The Gigaset - PRO Maxwell 10S has an endless array of features thanks to access to the Google Play Store. For example, you always have your online calendar at your fingertips or can use any app to make video calls. The hearing and speech quality of the device is also impressive. Only the enclosed manual is not very helpful, which complicates the setup.

read review
Yealink SIP T5 Series T53 - thumbnail Test seal: Yealink SIP T5 Series T53, Rating good

3rd place: Yealink SIP T5 Series T53

The Yealink SIP T5 Series T53 has all the basic requirements of an office telephone and convinces with intuitive operation. However, it hardly has any additional functions. Among other things, video telephony is missing.

read review
Tiptel Htek UC924E VoIP-Phone - thumbnail Test seal: Tiptel Htek UC924E VoIP-Phone, Rating good

4th place: Tiptel Htek UC924E VoIP-Phone

The Tiptel 'Htek UC924E' VoIP phone is a timeless office phone with all necessary functions and a high-quality design. It can convince in sound as well as operation. Unfortunately, the speaker mode is extremely stressful for the caller and therefore only suitable for very short and quiet conversations, if at all.

read review
Snom Global Desk Telephone D785 - thumbnail Test seal: Snom Global Desk Telephone D785, Rating good

5th place: Snom Global Desk Telephone D785

The Snom Global Desk Telephone D785 is ideal as a simple phone, but offers nothing more than that and is not as easy to set up as comparable products. Nevertheless, the sound quality is good and pleasant even for longer calls.

read review
Snom D735 Desk phone - thumbnail Test seal: Snom D735 Desk phone, Rating satisfactory

6th place: Snom D735 Desk phone

The Snom D735 desktop phone is easy to use and has a convincing sound. Therefore it is suitable for every office. Unfortunately, it offers almost no additional functions but makes up for this with a timeless design.

read review

Yealink - VP59 SIP Videophone

Winner: read review
  • First of all, you should look for a VOIP provider or a telephone system.
  • Does a network already exist and are there enough appropriate connections?
  • Is a WLAN-enabled device required?

In the run-up to the test, we defined practical requirements and established the following test criteria:

  • Scope of functions
  • Establishment
  • Operation
  • Call quality

To be able to evaluate these criteria, we have defined several tests for the office telephones. First, the scope of delivery is checked. The telephones are set up according to the manufacturer's specifications, and user-friendliness and effort are assessed.

In our tests we do not use a conventional telephone system, but the Internet telephony provider sipgate. Furthermore, the menu navigation and the existing functions are checked for all devices. During several telephone calls, the volume, clarity and connection of transmitter and receiver are assessed. Finally, it is tested whether the devices have additional functions such as apps, calendar and similar.

In order to rule out errors and to ensure that the devices are not subjected to the stress of everyday use, each test is carried out in several stages.

The test criteria are given percentages depending on their importance. The final mark is then calculated objectively from the test criteria using an algorithm.

Three of our tested office telephones
Three of our tested office telephones

Product selection

Our product selection is based on the observation of the current market. In addition to popular brand products, we also include insider tips in our selection. Criteria such as price and range of functions are an important factor for us. The test field is also determined by analysis and evaluation of customer reviews and external tests (e.g. Stiftung Warentest).

The devices are purchased anonymously or lent to us by the manufacturer. Dealers and manufacturers have no influence on the tests and our evaluation.

As soon as new relevant products come on the market, our test field will be expanded to include them. The new products undergo the same tests as the already tested devices.

Deutsche Telekom's ISDN switch-off has been in full swing not only since yesterday. Yes, actually the switch to Internet telephony should have been completed by 2018. The fact is, however, that ISDN will be a thing of the past for all private customers by the end of 2019. Business customers will be given an extra year to switch to Internet telephony.

Only with providers like Vodafone is ISDN an option for you until 2022. However, Internet telephony is not expected to bring about any visible changes in everyday working life in general.

While the telephone system migrates to the cloud, the desk phone will continue to adorn your office as always. Here you will learn all about the advantages and disadvantages of Internet telephony and the necessary precautions for a smooth transition to it.

Flexibility is the name of the game. Internet telephony, for example, listens to the name IP telephony as well as Voice over IP, or VoIP for short.

However, while no practical benefit can be derived from this variety of terms, the flexibility of the VoIP telephone system should convince you. The times are over when the stationary telephone system in operation causes high acquisition and maintenance costs. Instead, the virtual cloud telephone system takes over the setup and administration of extensions.

IP telephone from Tiptel.
IP Phone from Tiptel.

Depending on your needs, you can increase or reduce the contingent of options and phone numbers every month. The VoIP provider is only paid for what is needed. At the same time, the provision of the telephone system via the Internet allows you to use it wherever you are. It makes no difference whether you are in your home office or in the field, at the company location X or Y. You always have access to the IP telephone network of your company.

Possible end devices

In itself, all that is required is a VoIP provider with a virtual telephone system, a fixed-line Internet access with a fixed IP address, a computer and a headset for Internet telephony. Softphone is the name of the software on your computer that acts as a SIP phone.

The VoIP provider provides it to you free of charge. The alternative is an IP phone. Optically and functionally this does not differ from a conventional telephone. However, to connect your IP phone to the virtual PBX, you use an Internet cable instead of a telephone cable. Please note that VoIP providers do not support all IP devices equally.

Given the sheer list of manufacturers, you should be able to find one. Gigaset, Cisco, Panasonic, Yealink, Grandstream, and Polycom are just a few of the many that offer IP devices. Your smartphone can also be used with a corresponding app for IP telephony.

Not unlike the computer, the mobile device becomes a softphone, i.e. a SIP client. The conversion of analog phones with an adapter is basically possible but is not recommended for cost reasons. After all, the adapters are relatively expensive.

Wireless connection

At first glance, it may seem extremely tempting to use the free softphone to cover everyday office life. But it's no coincidence that the Gigaset T480HX desk phone is one of the top 100 office products of 2019, for example, and nothing has lost the appeal of the conventional office phone in the age of IP migration. Why should it? Many telephone users still appreciate the convenient operation of the large buttons on the wide housing.

The wireless handset from Gigaset.
The Gigaset Wireless Handset.

A 2.8" color display is always a sight to behold when a central 5-way button makes navigation a breeze. Especially during long conversations, it is advantageous if incoming calls can be seen directly on the display. While the day/night mode lets you determine your basic availability, a simple press of a button keeps annoying callers at bay.

Not unlike conventional office telephones, the IP desk telephones also come with a phone book that can hold up to 500 contacts. With Bluetooth or USB, these are stored in the PC in no time at all. However, one trend is emerging for IP desk telephones: wireless connection to telephone bases and VoIP routers.

This means that the office telephone is not bound to a specific location. Only the Bluetooth headset offers you more freedom. With it, you have your hands free for possible call notes.

The better accessibility

The independence from a physical telephone line allows you to use the so-called nomadic use. In other words: Simple internet access is sufficient for making phone calls, provided you have the appropriate VoIP software or hardware. Especially with a VoIP-capable smartphone, you can be reached not only on your mobile phone number but also on your landline number, both at home and abroad, and can make outgoing calls at landline rates.

The easy installation

Even as a bloody layman you are in good hands with IP telephony and don't need to worry about the configuration of your IP phone. Manufacturers such as Aastra or snom offer the option of setting up your end device via auto-provisioning. In practice, this means that you will be guided to a fully functional IP phone with step-by-step instructions in the login area of your PBX.

VoIP providers offer detailed instructions for many different devices and providers


Moreover, good VoIP providers do not skimp on detailed operating instructions. There is no shortage of explanations, especially for those end devices that VoIP providers explicitly recommend and support. And should you, contrary to expectations, still encounter problems, the VoIP providers themselves are always there to help you with advice and support. They will gladly take over the configuration of your IP phone for you.

The low costs

The cost reduction compensates for the work that naturally accompanies every technical conversion. So with IP telephony, you benefit from lower connection charges. Yes, there are no costs at all for internal company telephone calls. Not to forget the lower maintenance costs due to the automatic firmware updates.

If you're a proven eco-friend, you'll appreciate the proven low power consumption of IP phones. In short, IP telephony not only delivers sustainable productivity gains but also makes a visible contribution to green IT.

The excellent voice quality

The transmission quality of IP telephony is much better than that of ISDN telephony. However, this is only true if all devices involved in the telephone call support the G.722 voice codec. HD telephony or, to speak with cordless phones, CAT-iq is therefore out of the question if your phone, router, VoIP provider's server or the other party's equipment does not support G.722.

Efficient collaboration

In terms of functionality, the virtual telephone system is in no way inferior to the professional PBX. In addition to basic functions such as toggling, hold, three-party conferences or the use of busy lamps, a number of additional functions à la Interactive Voice Response or voice encryption are waiting for you. With over 150 functions, the UCC solution is as natural as the integration of CRM systems.

The UCC package of good VoIP providers promises seamless telephone integration, video conferences in HD, desktop & file sharing, instant messaging and presence as well as virtual conference rooms. With Salesforce, SugarCRM and Sage, the leading CRM systems can also be integrated. The complete integration of customer data in the PBX enables the identification of a caller before the call is effectively answered.

Retrofitting the hardware

The essence of IP telephony includes the compression of call data as well as the optimization of voice frequencies. Sometimes individual network devices of older models do not meet these requirements. Especially those devices of the telephone network which are subscribed to bit-precise transmission or interference immunity or simply to special ISDN functions are likely to encounter problems. This mainly affects alarm systems or credit card terminals, but also sometimes simple fax machines.

In general, therefore, telephone systems that have been in operation for more than five years will not be suitable for IP conversion. The purchase of a new expensive stationary ISDN system is not necessary, however, as long as a cost-effective alternative is available in the form of the much more flexible cloud telephone system.

Backup battery against power failure

A regional power outage usually does not affect a conventional telephone, as it is supplied with power from the fixed network. In contrast, your VoIP application will fail across the board in this case, especially since it's hooked up to the household power supply. However, this is not a serious problem, especially since you can simply use a backup battery to effectively deal with a possible power outage.

IP phone from SNOM.
IP Phone from SNOM.

Poor voice quality without an excellent Internet connection

Thanks to the available bandwidth and excellent error correction, ISDN calls are generally considered to be noise-free and crystal clear. Any interference is only expressed by a short crackling sound. However, dropouts and dropped calls are not to be expected. In IP telephony, on the other hand, voice quality sometimes fluctuates considerably. Even dropouts cannot be ruled out. It is probably your router's fault if it does not give VoIP data preferential treatment and does not allow enough bandwidth for intensive parallel use of the Internet.

The quality of the clarity of the conversation partner could also suffer from a smartphone whose mobile or WLAN connection is too weak. It is conceivable that the poor voice quality is simply due to an unstable DSL line. If your DSL modem resynchronizes several times a day, it is most likely the culprit.

Security through reliable encryption

It is not surprising that in the age of cyber-attacks, security is a major concern for many technology freaks. Even if IP telephony is not invulnerable, it is no more vulnerable than conventional ISDN telephony. On the contrary. In fact, the VoIP application even offers an additional shot of security, which you can easily implement with appropriate encryption concepts. Your VoIP provider will be happy to advise you if required and has the right security solution for you in no time at all.

Call setup that takes getting used to

It takes a while before the ringing tone sounds after dialing in IP telephony. This is because the VoIP router forwards the respective telephone number in its entirety to the server of your VoIP provider. Therefore, the router always waits a few seconds after each digit is entered to see if another digit follows. Only when it is sure that the telephone number is complete does it become active and populates the VoIP server. However, you are free to shorten the waiting time for the dial tone. If you press the phone's hash key after entering the last digit, you give the router free rein to transmit the telephone number.

The bandwidth is what counts

If you are about to convert your office phones to VoIP, it is advisable to first take a look at your current contracts. The forced conversion to IP is accompanied by a special termination right that guarantees you the premature end of unnecessary maintenance and provider contracts.

Of course, special ISDN services such as file transfers or door openers may also be affected by the termination. It is therefore up to you to provide an alternative in time to ensure the smooth continuation of these services.

Additional online services can also be used via the IP phone if the bandwidth is sufficient.
Other online services can also be used via the IP phone if the bandwidth is sufficient.

Please also note that the Internet connection must be left out during your wave of cancellations. After all, you also need Internet access for Internet telephony. Accidental termination of the Internet connection together with the telephone connection is certainly not a mishap. Switching to a new Internet provider even gives you the opportunity to save costs.

From a purely technical point of view, the be-all and end-all of a successful IP changeover is sufficient bandwidth. After the VoIP providers are useful with a full telephone connection, the appropriate local network numbers and a telephone book entry, the usual telephone connection of the Deutsche Telekom is obsolete.

However, an adequate Internet broadband connection is all the more important. The bandwidth of your ADSL or SDSL connection simply determines how many calls you can make in parallel. It is important to remember that not only your IP phones but also your computers and other network devices consume bandwidth.

To ensure the voice quality in IP telephony, you need at least 100 kbit/s per voice channel for pure VoIP traffic. The appropriate bandwidth is guaranteed to be half the way to success. Nevertheless, SIP telephony will not be successful if network components such as firewalls, switches, and routers block essential ports. To make your network truly VoIP-capable, you need to be receptive to Power over Ethernet (PoE) and Quality of Service (QoS). If these technical requirements are too high for you, let your VoIP provider do their job.

You should have 100Kbit/s available per voice channel and ensure voice quality


Registering with him is the next item on your to-do list anyway. Ideal is a provider who offers the possibility of a test phase. A serious VoIP provider should offer a 30-day free trial. It makes sense to use this time if you are flirting with number portability.

After all, porting is not done overnight. In principle, however, you have the choice of either using the old numbers or applying for new ones from your VoIP provider.

Now, at the latest, it is also the highest railway to change your telephone equipment to VoIP-capable terminals. Ideally, you should choose devices from the shop of your VoIP provider. This ensures that your technical equipment is always fully functional. In this respect, the devil should be in the fire if the free test turns out to be an absolute failure and switching to another VoIP provider is indicated.

Since the IP changeover basically requires nothing more than a suitable Internet router, which in the worst case has to be replaced in the case of outdated devices, the costs do not really matter. Even if the moderately complex analogue telephone system of your business line calls for replacement, the clamour is not appropriate. A cursory glance at the VoIP provider scene will tell you in no time at all that at Placetel, for example, the basic telephone system for 3 employees is available for free.

IP phone from SNOM.
IP Phone from SNOM.

Of course, telephony is much more expensive with 1.9 ct/min than in the PROFI version, for which you have to pay 2.90 € per extension. But in this VoIP solution telephony is already available from 1 ct/min. And that's not all. If you agree to 5.90 € per month per extension, a free Cisco IP end device will be offered as a bonus. And if your office work is mainly characterized by telephone calls, we recommend the optional purchase of the Allnet flat rate. These few figures from a single VoIP provider alone illustrate how important it is to put together the right IP telephony package for you based on your personal needs.

How do we test at

Live and authentic: We get the devices into our Hamburg test laboratory. Here we take a close look at everything.

Each test is preceded by an extensive search:

  • Which suppliers are on the market?
  • What current products are there?
  • What are the comparison criteria?
  • What tests are we going to run?
  • What is the test procedure?

When everything's settled, we'll bring the devices to us. For each product the test procedure, the measured values and product properties are documented in detail. We create photos and videos. We evaluate the results for you, summarize everything in a test report and calculate the test grade.

Have fun!

Rate this test


What is the best office phone?

Our test winner is the Yealink VP59 SIP Video Phone: The device has a high-resolution touch display, video telephony and convinces with intuitive operation. Our favourite with the test mark 9.3/10!

We have tested 6 office phones and paid special attention to the operation, setup and telephony.

The office telephone is indispensable for every workplace. By switching to IP telephony, the newer models have numerous functions that make everyday office life much easier.


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