• All charges must be displayed, usually manufacturers will provide a suitable notice, or the owner must make one.
  
• If the payphone is connected in parallel with other phones, the user must be made aware that calls could be overheard.
  
• Any emergency 999/112/222 call must be free of charge. (222 or 2222 is normally only used within Ministry of Defence property or UK dependent offshore territories - in such areas the 2222 numbers would normally route to a military emergency service)
  
• Payphones cannot be connected in the same circuit as series connected devices like fax machines.
  
• Within the UK the 112 number also works.

NB. VOIP services don't always offer emergency service numbers, care must be taken to ensure that if you offer a payphone service based on VOIP that you must offer access to emergency services. Some VOIP services now offer emergency service access following extensive address and account verification procedures, but it should be noted that these services are often located in another country, the operators of which may have to lookup telephone numbers for appropriate support and this could seriously delay assistance in the event of an emergency. It is therefore prudent to have an alternative form of emergency dialling available. We can provide voIP integration into ISDN.