05 Numbers

Corporate and VOIP phone numbers

UK telephone numbers beginning '05' fall into one of two categories:

055 corporate numbering

These numbers are intended for large organisations who require dedicated blocks of telephone numbers that are not associated with a specific locality – such as for an internal phone network spanning various branches around the country.

In practice, few companies have introduced 055 numbers and they remain rare. Most companies use 03 or 08 numbers instead, or simply acquire a single large block of normal geographic numbers in an area with plenty of spare capacity.

Current corporate numbering in use consists of:

  • 05511 numbers
  • 05516 numbers
  • 05555 numbers
  • 05588 numbers

056 VOIP and similar

Officially designated for 'location independent electronic communication services', 056 numbers are mostly used for VOIP phone services. Such services have also been able to use standard '01' and '02' area codes since late 2004.

Current numbering in use consists of:

  • 05600 numbers
  • 05601 numbers
  • 05602 numbers
  • 05603 numbers

More information

There are no set rules for how 05 numbers should be presented, although the format 05xxx xxxxxx seems most common.

0500 numbers were used for freephone services, until their withdrawal during 2017.

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