Phone Lines in Hotels

There are three phone line options for Hotels; ISDN, Phone Line+ and SIP. However, ISDN is slowly being phased out, to be switched off in 2025.

For smaller hotels,Phone Line + is a viable option but for larger hotel opterations, we recommend SIP Trunks unless you are upgrading your whole phone system, which means you could bypass the need for SIP if you choose a Hosted Phone System.

Discover more about the benefits of SIP.

ISDN Phone Lines

ISDN (Integrated Service Digital Network) is a very traditional solution which uses physical copper and fibre optic lines to connect via telephone exchanges across the world.

As previously mentioned, ISDN is being phased out. From September 2023 you will no longer be able to purchase any additional ISDN phone lines. Between April and December 2025, there will be a forced migration period before they switch them off.

This means you can still use ISDN phone lines until September 2023 but since it is out-dated technology, it is worth looking at alternatives, now, especially if you have plans to grow.


Phone Line + has been designed to replace traditional landlines using VoIP technology to deliver voice calls over the broadband network.

Phone Line + is an easy-to-use software-based solution that is updated and maintained remotely. As an Administrator of your PhoneLine+ account, you’d have complete control over users; easily adding/removing users, allocating your phone numbers, and changing privacy settings such as including any numbers that you want to block.

With Phone Line +, you’ll be able to:

  • Access from any Device
  • Manage more than one number
  • Use Key Features such as Voicemail, Call Divert, Call Hold, Contact Directory, Call Transfer, Call Forwarding and Number Withholding.
  • Set an Out of Hours profile 
  • Store business essential phone numbers
  • Receive email notifications of missed calls and voicemails
  • Access Call Analytics 

SIP Trunks

SIP is cheaper on a per-line basis than ISDN and, it offers flexibility, control over your phone numbers and they are quicker to install.

SIP uses virtual phone lines, created over your internet connection rather than physical wires.

Most people will see SIP and SIP Trunking and wonder what the difference is;

  • Session Initiation Protocol (SIP) is the set of rules that allows you to initiate and terminate a communication session, whether it’s a voice call between 2 people or multiple calls between a whole team, using an IP address.
  • SIP trunking is the service that allows you to put this protocol into use on a public network.
  • Save Money on call costs and line rental – IP connectivity costs less than ISDN so you’ll benefit from lower call costs; free internal calls between sites and free calls to UK local/national and mobiles. 
  • Flexibility with phone numbers – You can easily port your existing numbers across and SIP enables you to reduce the number of PBX’s you need to maintain whilst maintaining your existing phone number(s) regardless if you move office.
  • Compatibility – SIP is fully compatible with all modern phone systems.
  • Scalability – SIP Trunks are perfect if you are growing (or even downsizing) and you want to retain your phone numbers. You are always in control because you can add phone lines, remove lines and split calls on demand. There are no limits to the number of lines you can use, simultaneously.
  • High Quality – We can proactively monitor and manage the quality of service across the entire network – it’s the underlying network quality that makes a real difference to SIP trunking. This means that we are able to support both G.729 or G.711 codecs.
  • Business Continuity – Should your hotel or operations need to be relocated, SIP trunking allows you to take your phone lines with you quickly and cost-effectively.
  • Easy to Deploy – SIP is fast and easy to deploy and can scaled up and down, on -demand and quickly. 

SIP Trunk Call Manager vs Inbound Call Manager

SIP Trunk Call Manager is integrated directly with your SIP lines and it can be deactivated or activated as needed. Inbound Call Manager is a standalone product.

They are similar in features but Inbound takes it further by enabling it to be activated on to mobiles and other phone lines.

Essentially, they both give you the ability to manage your entire number estate and all aspects of your inbound calls so that you have full control and don’t have to rely on a network operator to make changes for you.

STCM and Inbound both help improve your business’s customer service by ensuring all calls are managed by the right people, consistently, throughout quiet and busy periods. They allow you to consolidate all your numbers onto a single platform and never miss a call! You can make changes using a mobile app or the online portal.

Learn more about how SIP can help your business

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