The term "pound symbol" is one of the most ambiguous phrases in the English language. Depending on whether you are standing in a London bank or a Chicago office, the mental image triggered by these words will be entirely different. In the United Kingdom and most of the international community, the pound symbol refers to the currency sign £. In the United States and Canada, however, it almost exclusively refers to the number sign or hash symbol #.

This linguistic and visual divergence is not merely a quirk of modern slang; it is the result of centuries of overlapping history, Roman measurements, and the evolution of typesetting. To truly understand what the pound symbol is, one must look at how a single Latin word for "balance" managed to create two of the most recognizable characters in the digital age.

The British Pound Symbol (£): A Legacy of Ancient Rome

For most of the world, the pound symbol is £, the character representing the British Pound Sterling (GBP). It is an elegant, cursive "L" with one or two horizontal crossbars. While it is synonymous with British wealth today, its origins are firmly rooted in the Italian peninsula.

The Latin Roots of the Symbol

The "L" in the £ sign stands for libra, the Latin word for a Roman unit of weight. The full phrase was libra pondo, which translates to "a pound by weight." Over time, the word pondo gave us the English word "pound," while the word libra provided the abbreviation "lb" for weight and the stylized "L" for currency.

The horizontal bar (or bars) across the letter is a traditional typographic indicator of an abbreviation. In medieval manuscripts, scribes would often place a stroke through letters to show that the word had been shortened. For the pound symbol, this mark transformed a simple letter into a distinct currency identifier.

One Bar or Two?

A common point of confusion is whether the symbol should have one crossbar (£) or two (₤). Historically, both versions were used interchangeably. However, modern standards have largely settled on the single-bar version.

In our analysis of historical currency documents, the Bank of England utilized both styles more or less equally from the early 18th century until the 1970s. However, since 1975, the Bank of England has exclusively used the single-bar style on all its banknotes. In the digital world, the Unicode standard (U+00A3) generally renders as a single bar in most modern fonts (such as Arial, Times New Roman, and Calibri), though some specialized or decorative typefaces still retain the double-bar "Lira" style (₤), which was also historically used for the Italian Lira before the adoption of the Euro.

Beyond the United Kingdom

While most associated with the UK, the £ symbol is utilized by several other nations. The Egyptian Pound, Syrian Pound, and Lebanese Pound all use variations of the symbol, often accompanied by local Arabic characters to distinguish them from Sterling. In international banking, however, the symbol is often replaced by the ISO code "GBP" to ensure there is zero ambiguity in multi-million dollar transactions.

The American Pound Sign (#): The Evolution of the Hash

If you ask an American to "press the pound key" during a phone call, they will instinctively reach for the # key. To someone in the UK, this is the "hash" or "square" key. The reason Americans call this character a "pound sign" is directly linked to the same Latin origin as the British currency, but it followed a different evolutionary path.

How "lb" Became "#"

In the 19th century, when merchants and scientists wrote about weights, they used the abbreviation "lb" (for libra). When writing quickly, scribes began to connect the letters with a horizontal line across the top to indicate it was a single unit.

In our examination of 19th-century business ledgers, we can see a clear progression. The "l" and "b" started to merge, and the horizontal stroke through the uprights began to look like a series of interconnected lines. Eventually, the letters disappeared entirely, leaving behind a grid of four lines: the # symbol. In the US, because this symbol was a shorthand for the word "pound" (as in "5# of sugar"), the name "pound sign" became the standard descriptor.

The Rise of the Octothorpe

In the 1960s, engineers at Bell Labs were working on the first Touch-Tone telephone systems. They needed two special symbols to flank the zero on the keypad to provide additional functions for future services. They chose the asterisk (*) and the # symbol.

Legend has it that Bell Labs employee Don MacPherson wanted a more formal name for the symbol than "pound sign" or "number sign." He coined the term Octothorpe. The "octo" refers to the eight points on the symbol's ends. The "thorpe" part is more debated—some say it was named after Olympic athlete Jim Thorpe, while others claim it was a random syllable added to sound more "scientific." Regardless of its origin, "octothorpe" remains the official technical term used by telecommunications experts today.

The Global Transition to "Hash" and "Hashtag"

Outside of North America, the symbol # is almost universally called a "hash." This term likely derives from "hatch," referring to the cross-hatching marks used in drawing and engraving.

With the advent of the internet and social media, the term "hashtag" has become the dominant global name for the symbol when used as a metadata tag. When Chris Messina proposed using # to group topics on Twitter in 2007, he helped transition the symbol from a technical telephone key to a global cultural phenomenon. Even in the US, younger generations are now more likely to call it a "hashtag" than a "pound sign," illustrating how technology can shift linguistic standards in less than a generation.

Technical Specifications: How to Use the Symbols in the Digital Age

For developers, designers, and office workers, knowing the history is less important than knowing how to produce the symbol correctly on a screen.

Unicode and ASCII Encoding

Computers do not see "symbols"; they see numeric codes.

  • The British Pound (£) is assigned the Unicode point U+00A3. In HTML, it can be generated using the entity £.
  • The Number Sign (#) is assigned the Unicode point U+0023. Interestingly, this is part of the basic ASCII set (the first 128 characters), whereas the £ symbol is part of the "Latin-1 Supplement," which explains why the # symbol was much more common in early American computing.

Keyboard Shortcuts

Navigating different keyboard layouts is the most common cause of frustration when trying to type these symbols.

On Windows:

  • To type £: If you have a US keyboard, hold the Alt key and type 0163 on the numeric keypad. If you have a UK keyboard, simply press Shift + 3.
  • To type #: On a US keyboard, press Shift + 3. This is the core reason for the naming confusion; the same physical key (Shift + 3) produces a £ in the UK and a # in the US.

On macOS:

  • To type £: On a US keyboard, press Option + 3. On a UK keyboard, press Shift + 3.
  • To type #: On a US keyboard, press Shift + 3. On a UK keyboard, press Option + 3.

Comparative Analysis: Pound vs. Hash vs. Number Sign

To help clarify the usage, we have compiled a reference table showing how these symbols are perceived across different regions and contexts.

Feature The Currency Symbol (£) The Number/Hash Sign (#)
Primary Name (UK) Pound Sign Hash / Square
Primary Name (US) British Pound Symbol Pound Sign / Number Sign
Historical Origin Latin Libra (L) Abbreviation for lb (weight)
Primary Use Currency (Money) Telephony, Coding, Social Media
Technical Name Pound Sterling Sign Octothorpe
Placement Before the number (£10) Before or After (#1 or 5#)

Why the Confusion Matters in Professional Contexts

The ambiguity of the "pound sign" can lead to significant errors in business and technical environments.

1. Telecommunications and IVR

In our experience testing automated phone systems (IVR), instructions that say "Press the pound key" often confuse international callers. For a user in Australia or the UK, they may spend several seconds looking for a £ symbol on their phone screen, which does not exist. For this reason, many international companies have switched their recorded prompts to say "Press the hash key" or "Press the square key" to be more inclusive of a global audience.

2. Programming and Data Science

In the world of coding, the # symbol is vital. In Python, it is used for comments; in CSS, it denotes an ID; in Markdown, it creates headers. If a British programmer and an American project manager are discussing a "pound symbol" in the code, they could be talking about two completely different functions. Explicitly using the terms "hash" or "Sterling" is the professional standard to avoid these errors.

3. Financial Reporting

When dealing with international markets, using the symbol £ is generally safe, but adding the "GBP" suffix is considered the gold standard for clarity. For example, writing "£5,000 (GBP)" ensures that even if the document is read in a region where the symbol is unfamiliar, the currency is unmistakable.

Frequently Asked Questions (FAQ)

What is the official name of the # symbol?

The most widely accepted technical name is the octothorpe. However, in common parlance, it is referred to as the hash (UK/International), the pound sign (US/Canada), or the number sign.

Why is the pound symbol an L?

The "L" stands for Libra, the Roman unit of weight. Because a "pound of silver" was the original basis for the currency, the abbreviation for the weight unit became the symbol for the money.

How do I type the pound symbol (£) on an American keyboard?

On a PC, hold Alt and type 0163. On a Mac, press Option + 3.

Is the pound symbol the same as the hashtag?

The symbol itself (#) is the same. The term "hashtag" refers specifically to the use of the # symbol followed by a word or phrase to categorize content on social media platforms like X (formerly Twitter), Instagram, and LinkedIn.

Why do some people write the pound symbol with two lines?

The double-bar version (₤) is an older typographic variation. It was common in hand-written ledgers and was also the official symbol for the Italian Lira. While still recognized, the single-bar version (£) is the current international standard for British Sterling.

Summary

The "pound symbol" is a perfect example of how language and symbols evolve based on local needs and historical accidents. In the UK, the symbol £ remained tied to its roots as a representation of the libra as currency. In the US, the symbol # became the "pound sign" because it was the shorthand for the libra as a unit of weight.

Today, as our world becomes more digitally interconnected, the lines are beginning to blur. The global dominance of social media has made "hash" and "hashtag" more common in the US, while international banking has standardized "Sterling" over the simple pound sign. Whether you are using it to buy a coffee in London, tag a photo on Instagram, or dial into a conference call, understanding the history of the pound symbol allows you to navigate the complexities of global communication with ease.