If you going to work in London and don’t know how to get a phone number, here’s an example. The zip code in national format (those without the + symbol) can be chosen for local users, then according to ITU-T standard E.123, you can display that area code inside parenthesis. Although the paired “three – three – four” structure is the same across all regularly used forms in the US and Canada, punctuation marks and periods are additional. It is officially recommended to employ gaps and extra parentheses simply.
In certain states, the same geographic location is served by several zip codes. In this situation, you cannot simply enter ten digits; instead, you must first dial a 1 to inform the machine that a postcode is coming, accompanied by the interchange code and the contact number (sometimes known as “1 plus 10” dialling). Even if the client you are phoning lives down the street, you still need to do this.
The second set of three digits, serving up to 10,000 lines, is a different exchange number. This can define a somewhat tiny geographic area in urban settings. This area could be significantly greater in rural areas. The interchange code’s first number is never 0 or 1.
Can you determine the location of a number?
With this straightforward technique, Google can clearly and quickly identify a phone number on a website based on the format of the number as well as nearby textual cues like a ‘Tel.’ or ‘Fax.’ or ‘call.’ prefix or the presence of a postal address right before it.
However, it’s quite doubtful that Google—or even a human—would instantly recognize a US phone number written as 21234-54567 or as 21.23.45.45.67 as being a US phone number if you did. An example of such a number is (212) 345-4567. In fact, the first example appears to be a Greek phone number, whereas the second example appears to be a French phone number.
The United Kingdom
The US and most of the remainder of the globe use a small variety of straightforward numbering systems, but not the UK. There are a few complications in the UK. The UK is divided into more than 650 areas, and the lengths of the areas vary. Before the postcode, dial other locations using the 0 trunk code. You can call local numbers with or without using the mixed trunk code and area code. After the 0 trunk code, area codes can have two to five digits, and the local number portion can have four to eight digits.
After the first 0 trunk code, most numbers have exactly ten numbers, although certain regions only have nine. Area codes for longer local numbers are smaller. When calling the UK from abroad, the 0 trunk code is omitted.
Incorrect number
Several regions of the UK received brand-new area codes in 1995 (PhONEday – five 011x codes), 1998 (Reading – the 0118 code), and 2000 (Big Number Change – five 02x codes), which also raised the length of local numbers in those regions by one or two digits. For the next ten years, many people who misunderstood the alterations wrote their phone numbers in the incorrect format. It goes without saying that if you want search engines to recognize the phone numbers shown on your website but are formatted incorrectly, this may have significant SEO ramifications, particularly for local search.
London
The appropriate format is (020) 7xxx XXXX, where 020 denotes London and the next four digits denote the specific provider or interchange. London contains numbers with the prefixes 8xxx XXXX and 3xxx xxxx as well.
All of those, except for four, “mask” the genuine area code and the interchange code (the next four digits after the 020 area code). In fact, when in the early 1990s, when area codes were six digits, 0203 was the old code for Bodmin (now 028), 0207 was the old code for Consett (now 01207), and 0208 was the old code for Coventry (now 024, briefly 01203 from 1995 to 2000).
Coventry
The correct syntax is (024) 76xx XXXX, where 024 denotes Coventry, and the following four digits denote the specific provider or exchange. Numbers in Coventry also start with the prefix 77xx XXXX. This also relates to all Cardiff (029) 20xx xxxx and 21xx xxxx numbers, all Northern Ireland (028) xxxx xxxx numbers, all Southampton (023) 80xx xxxx and 81xx xxxx numbers, and all Portsmouth (023) 92xx xxxx and 93xx xxxx numbers.
Sheffield
The appropriate format is (0114) 2xx XXXX, where the first digit 0114 denotes Sheffield, and the next three denote the specific exchange or provider. Sheffield has numbers that start with 3xx xxxx as well.
The same holds true for all Leeds (0113) 2xx xxxx, 3xx xxxx, and 8xx xxxx numbers, all Sheffield (0114) 3xx xxxx numbers, all Nottingham (0115) 7xx xxxx, 8xx xxxx, and 9xx xxxx numbers, all Leicester (0116) 2xx xxxx, 3xx xxxx, and 4xx xxxx numbers, all Bristol (0117) 2xx xxxx, 3xx xxxx, and 9xx
Is that eatery in Sheffield or So Paulo?
We’ll make up an example (primarily because we don’t want to use a real client) of a restaurant serving south American cuisine in Sheffield, UK, that hosts its website in the US, uses the.com TLD, and has material for its website in both Portuguese and English.
Why make a risk when correctly formatting a number is so easy to do?

Currently, up to 30% of all UK phone number information on the internet is either wrong, outdated, or structured incorrectly. Discovering a website without formatting errors is uncommon, particularly when using the 011x and 02x area numbers.
Confusing to visitors
Dialling locally in certain places has issues due to improper formatting. The common wisdom is to omit the area code in that area, and most of the world still abides by this basic guideline today.
Code ignorance
Many natives will have an incorrect understanding of the area code in places where incorrect formatting has been the standard for many years. For numbers in the ‘new’ ranges stated above, individuals are inadvertently dialing an unnecessary digit after the real area code and end up dialing the wrong number; for example, for the new number (0114) 345 4567, people are accidentally dialing 01142 345 4567 and are instead connected to (0114) 234 5456. In all of the locations listed in table 2, numerous reports of such dialing errors exist.
Pollution of Data
Most folks increasingly persuaded that the incorrect area number provided above is somehow accurate. They are also starting to format other area codes improperly that have never before caused an issue. Or they are coming up with more creative ways to make mistakes.
That is, somebody in Manchester who is familiar with viewing digits like (0161) 555 8899 will now wrongly type the Southampton number (023) 8044 7799 as 0238 044 7799 and the Dundee number (01382) 557799 as 0138 255 7799.
Plan for UK National Telephone Numbers
Currently, most UK numbers have ten digits following the zero trunk code, while a handful only has nine. This briefly overviews the appropriate syntax for each UK number range. The area codes are detailedly listed on a few different websites.
To make it apparent how to understand this, a “2+8” format number has an eight-digit local number. Plus a two-digit area code that comes after the 0 trunk prefix. After the 0 trunk prefix, a “4+6” format number has a four-digit area code and a six-digit local number.
Worldwide Format
Up to this point, we have only talked about numbers that are written in the national format. Such as (020) xxxx xxxx and (01×1) xxx XXXX. Include only the numbers that international callers MUST dial. Do NOT include the leading zero trunk code for UK numbers. You should write +44 20 7234 3456 for a London number as an example. And not +44 (0) 20 7234 3456 or +44 020 7234 3456. For more details, see ITU-T Recommendation E.123. Naturally, if you are quoting an Italian phone number, you would type +39 06 456 4455. Since you must still dial the zero when contacting a number from another country.
Conclusion
When using the phone number example for London, you need to make sure you’re using a service that works with every type of phone. You don’t want to give someone a number that they will never be able to call. Once you have a service picked out, there are many different ways it can be utilized.