Ofcom numbering data

What it is

Ofcom publishes the National Telephone Numbering Plan’s blocks, range by range: which are allocated and to which communications provider, which are free, and which are protected or quarantined. Numbers in Guernsey, Jersey and the Isle of Man sit in the UK +44 plan and are read from the same tables.

What the copy installed here holds

Counts only. Holders are counted, never named, and no row of the table is republished here: the publisher’s own files are linked below. A version marked “retrieved on” is the day the file was fetched, because the file itself carries no date.

How the rows read, and what a number outside them answers

Allocated blocks read as allocated to their provider; designated blocks as reserved; free, protected, quarantined and reserved blocks as unassigned.

Ofcom’s table is not treated as complete: a number outside every listed block is not evaluated, and its block_status answers null.

The files

• s1.csv, s3.csv, s5.csv, s7.csv, s8.csv, s9.csvSix CSV files (Ofcom also offers them as XLSX), one per leading digit; the files carry no date. Geographic (01 and 02), 03, 05, 07, 08 and 09 number blocks with their status and provider.

The terms, as the publisher states them

The numbering data page states no licence; its footer reads “© Ofcom 2026”. Ofcom’s copyright page says its material “may be reproduced free of charge in any format or medium, provided that it is reproduced accurately and not used in a misleading context”, and that it “must be acknowledged as Ofcom copyright”. Its open data page adds: “Where we can make the data available on an open basis, we use the Open Government Licence”.

terms checked 2026-09-26

What the table cannot say

• A regulator’s table records the original allocation of each block, never who serves a number today: a number ported to another carrier keeps its block.
• An allocated block says a number in it can be in service, not that it is.
• The counts are rows of the regulator’s own table, not numbers or traffic: a busy block and an empty one count once each.
• Ofcom lists free, protected and quarantined blocks row by row, so an unassigned answer always comes from Ofcom’s own row and never from a block missing from the files.
• Guernsey, Jersey and the Isle of Man have their own regulators; their numbers are read from this table because they sit in the UK plan.

The risk signals read from it

• reserved_block · the regulator's table marks the block reserved (+40)
• virtual · the block is held by a virtual-number wholesaler or VoIP provider (+40)

The other sources of a phone answer

• NANPA numbering reports
• CNAC central office code status
• ARCEP numbering resources
• ACMA numbering register
• ACM number register
• NAD number register
• Mexico’s national numbering plan
• UKE numbering tables
• MIMIT assigned numbering
• libphonenumber
• SMS-receiving number lists
• FTC Do Not Call reported calls
• Every source, and the regulators not synced
• Where each field comes from
• Look up a number

counts read from the installed tables · terms checked 2026-09-26