Open vs Closed Numbering Plans

Spain's national numbering plan is closed. The ministry's numbering-plan page says the plan approved by Real Decreto 2296/2004 is a closed nine-digit plan: the caller always dials all nine digits, wherever they are, and abbreviated local dialling is not possible. There is no trunk prefix to remove.

A landline that starts with 8 or 9 keeps that digit after +34. A mobile that starts with 6 keeps the 6. Numbers beginning 71, 72, 73, and 74 are also nine-digit mobiles, under the resolution of 12 March 2010 (BOE-A-2010-5251), which extended mobile numbering alongside numbers beginning with 6. Code 70 is personal numbering and is outside that resolution. The ministry attributes mobiles to 6, and provincial indicatives to 9 and 8. Those indicatives sit inside the nine digits. They are not a trunk prefix.

The international prefix is 00. That is the ITU dialling list of 15 December 2011 (annex to Operational Bulletin No. 994: country code 34, international prefix 00, national significant number 9 digits) and the Spain country page. The trunk cell in that ITU row is not a digit. Do not read a blank trunk cell as "Spain has no area codes".

Ofcom's statement on geographic numbering, published 11 March 2022, says: "The UK has an 'open dialling plan' to facilitate consumer dialling of local phone numbers." The next sentence says landline calls to geographic numbers in the same area as the caller can be dialled without the area code. In the National Telephone Numbering Plan in force from 22 April 2025, local dialling is "the ability for a Calling Party to contact a Called Party within the same Geographic Area Code area by dialling only the Local Number".

That is not every UK call. Ofcom's numbering page, last updated 3 February 2026, records for the version in force on 11 March 2022: "Removal of the local dialling requirement." The statement of that date removes the obligation on providers to provide local dialling, with effect from publication. The same plan still says local dialling shall not be provided in six area codes. The statement already described that exception.

The domestic trunk prefix is still 0. Paragraph B2.1 of the plan in force from 22 April 2025 says public communications network numbers in Part A1 "shall comprise ten (10) digits (excluding the national prefix code '0') unless otherwise indicated in that Part or in the National Numbering Scheme." The international prefix is 00 (ITU list of 15 December 2011: country code 44, national prefix 0; also the United Kingdom page). This page does not take the UK length from the 2011 list.

France still has a trunk 0 that is dropped after +33. It is not the example for either dialling rule on this page. Arcep's page "La numérotation", updated 14 September 2026, describes ordinary French numbers as ten-digit national numbers, form EZABPQMCDU, not as a short local number plus a trunk prefix. Mobiles begin 06 and 073 to 079. Numbers beginning 0700 are 14-digit machine-to-machine numbers, so nine significant digits is not every French range. The ITU list of 15 December 2011 gives France international prefix 00, national prefix 0, and a national significant number of 9 digits. The France page says drop the trunk 0 from the ten-digit domestic number and keep nine digits.

The trunk prefix is the digit dialled inside the country to reach the trunk network, before the area code, when the call leaves the local numbering area. ITU-T recommends a single digit, preferably 0, and that this digit not also be the first digit of the national significant number.

Spain has no such prefix: the 8 or 9 on a landline is part of the nine digits. The UK uses 0 on the national form. Where local dialling is still provided, a same-area call may omit the area code.

The trunk prefix is not part of the national significant number, on an open plan or on a closed plan, so it is not dialled after the country code. ITU-T E.164 section 7.3.2, as excerpted for the February 2026 recommendation, says it must not be dialled at the international level. What drops is the prefix, not "a zero", and not because the plan is open.

A leading 0 stays only when the destination plan defines it as part of the national significant number. That is the Italian geographic case. This page does not walk it through. See international dialling format and Italy.

X is a placeholder, not a subscriber number.

• United Kingdom: 0XX XXXX XXXX is dialled as +44 XX XXXX XXXX. The area code stays.
• France: 0X XX XX XX XX becomes +33 X XX XX XX XX.
• Spain: +34 plus all nine digits. Do not strip an 8 or a 9. 6XX XXX XXX stays +34 6XX XXX XXX. 9XX XXX XXX and 8XX XXX XXX stay whole.

Keeping a trunk 0 after the country code is a formatting error. See formatting errors.

This page will not choose a carrier-selection code, a PBX prefix, or whether a particular UK area still allows local dialling. Use the United Kingdom page and the current numbering plan for that area code.

If you are storing the number, store +, the country code, and the national significant number. Do not store the exit code, and do not store a trunk 0 that the destination plan says to drop. Storage layout is the forms, CRM, and SMS guide.