Premium Bonds is a
lottery bond scheme organised by the
United Kingdom government
His Majesty's Government, abbreviated to HM Government or otherwise UK Government, is the central executive authority of the United Kingdom of Great Britain and Northern Ireland. since 1956. At present it is managed by the government's
National Savings and Investments
National Savings and Investments (NS&I), formerly called the Post Office Savings Bank and National Savings, is a state-owned savings bank in the United Kingdom. It is both a non-ministerial government department and an executive agency of HM T ...
agency.
The principle behind Premium Bonds is that rather than the stake being gambled, as in a usual
lottery
A lottery (or lotto) is a form of gambling that involves the drawing of numbers at random for a prize. Some governments outlaw lotteries, while others endorse it to the extent of organizing a national or state lottery. It is common to find som ...
, it is the
interest
In finance and economics, interest is payment from a debtor or deposit-taking financial institution to a lender or depositor of an amount above repayment of the principal sum (that is, the amount borrowed), at a particular rate. It is distinct f ...
on the bonds that is distributed by a lottery. The bonds are entered in a monthly
prize draw and the government promises to buy them back, on request, for their original price.
The government pays interest into the bond fund (4.15% per annum in December 2024 but decreasing to 4% in January 2025)
from which a monthly lottery distributes tax-free prizes to bondholders whose numbers are selected randomly. The machine that generates the numbers is called ERNIE, an acronym for "Electronic Random Number Indicator Equipment".
Prizes range from £25 to £1,000,000 and (since December 2024) the odds of a £1 bond winning a prize in a given month are 22,000 to 1.
Investors can buy bonds at any time but they must be held for a whole calendar month before they qualify for a prize. As an example, a bond purchased mid-May must then be held throughout June before being eligible for the draw in July (and onwards). Bonds purchased by reinvestment of prizes are immediately eligible for the following month's draw.
Numbers are entered in the draw each month, with an equal chance of winning, until the bond is cashed. As of 2015, each person may own bonds up to £50,000. Since 1 February 2019, the minimum purchase amount for Premium Bonds has been £25. there are over 128.7billion eligible Premium Bonds, each having a value of
£1.
When introduced to the wider public in 1957, the only other similar game available in the UK was the
football pools
In the United Kingdom, the football pools, often referred to as "the pools", is a betting pool based on predicting the outcome of association football matches taking place in the coming week. The pools are typically cheap to enter, and may enc ...
, with the
National Lottery not coming into existence until 1994. Although many avenues of lotteries and other forms of gambling are now available to British adults, Premium Bonds are held by more than 24 million people,
equivalent to more than 1 in 3 of the UK population.
History
The term "premium bond" has been used in the
English language
English is a West Germanic language that developed in early medieval England and has since become a English as a lingua franca, global lingua franca. The namesake of the language is the Angles (tribe), Angles, one of the Germanic peoples th ...
since at least the late 18th century, to mean a
bond that earns no interest but is eligible for entry into a lottery.
The modern iteration of Premium Bonds were introduced by
Harold Macmillan
Maurice Harold Macmillan, 1st Earl of Stockton (10 February 1894 – 29 December 1986), was a British statesman and Conservative Party (UK), Conservative politician who was Prime Minister of the United Kingdom from 1957 to 1963. Nickn ...
, as
Chancellor of the Exchequer
The chancellor of the exchequer, often abbreviated to chancellor, is a senior minister of the Crown within the Government of the United Kingdom, and the head of HM Treasury, His Majesty's Treasury. As one of the four Great Offices of State, t ...
, in his
Budget
A budget is a calculation plan, usually but not always financial plan, financial, for a defined accounting period, period, often one year or a month. A budget may include anticipated sales volumes and revenues, resource quantities including tim ...
of 17 April 1956, to control inflation and encourage people to save.
On 1 November 1956, in front of the
Royal Exchange in the City of London, the
Lord Mayor of London
The Lord Mayor of London is the Mayors in England, mayor of the City of London, England, and the Leader of the council, leader of the City of London Corporation. Within the City, the Lord Mayor is accorded Order of precedence, precedence over a ...
,
Alderman
An alderman is a member of a Municipal government, municipal assembly or council in many jurisdictions founded upon English law with similar officials existing in the Netherlands (wethouder) and Belgium (schepen). The term may be titular, denotin ...
Sir
Cuthbert Ackroyd, bought the first bond from the Postmaster General, Dr
Charles Hill, for £1. Councillor William Crook, the mayor of
Lytham St Anne's, bought the second. The Premium Bonds office was in
St Annes-on-Sea, Lancashire, until it moved to
Blackpool
Blackpool is a seaside town in Lancashire, England. It is located on the Irish Sea coast of the Fylde peninsula, approximately north of Liverpool and west of Preston, Lancashire, Preston. It is the main settlement in the Borough of Blackpool ...
in 1978.
Winning
Winners of the jackpot are told on the first working day of the month, although the actual date of the draw varies. The online prize finder is updated by the third or fourth working day of the month. Winners of the top £1m prize are told in person of their win by "Agent Million", an NS&I employee, usually on the day before the first working day of the month. However, in-person visits were suspended, starting in May 2020, during the
COVID-19 pandemic in the United Kingdom
The COVID-19 pandemic in the United Kingdom is a part of the worldwide pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In the United Kingdom, it has resulted in confirm ...
.
Bond holders can check whether they have won any prizes on the National Savings & Investment ''Premium Bond Prize Checker'' website, or the smartphone app, which provides lists of winning bond numbers for the past six months. Older winning numbers (more than 18 months old) can also be checked in the ''
London Gazette
London is the capital and largest city of both England and the United Kingdom, with a population of in . Its wider metropolitan area is the largest in Western Europe, with a population of 14.9 million. London stands on the River Tha ...
Premium Bonds Unclaimed Prizes Supplement''.
Odds of winning
In December 2008, NS&I reduced the interest rate (and therefore the odds of winning) due to the drop in the Bank of England base rate during the
Great Recession
The Great Recession was a period of market decline in economies around the world that occurred from late 2007 to mid-2009. , leading to criticism from members of Parliament, financial experts and holders of bonds; many claimed Premium Bonds were now "worthless", and somebody with £30,000 invested and "average luck" would win only 10 prizes a year compared to 15 the previous year.
Investors with smaller, although significant, amounts would possibly win nothing.
From 1 January 2009 the odds of winning a prize for each £1 of bond was 36,000 to 1. In October 2009, the odds returned to 24,000 to 1 with the prize fund interest rate increase. The odds reached 26,000 to 1 by October 2013 and then reverted to 24,500 to 1 in November 2017.
, the odds of winning are 1/22,000; resulting in the expected number of prizes for the maximum £50,000 worth of bonds being 27 per year.
Prize fund distribution
The prize fund is equal to one month's interest on all bonds eligible for the draw. The annual interest is set by NS&I and was 1.40% , reducing to 1.00% . This was increased to 2.2%, then increased again to 3% and is now at 3.8% from April 2025. The following table lists the distribution of prizes on offer in the January 2025 draw.
Economic analysis
While the mean return is 3.8% as of April 2025, the
median
The median of a set of numbers is the value separating the higher half from the lower half of a Sample (statistics), data sample, a statistical population, population, or a probability distribution. For a data set, it may be thought of as the “ ...
return is lower. For an investor with the maximum £50,000 invested, the median return is 3.3% (£1,650). For investors with lower amounts invested, the median return is lower. The typical investor with £1,250 or less invested will receive nothing in a year.
Premium Bonds are tax free, so are more attractive to higher rate taxpayers.
ERNIE

ERNIE – an acronym for "Electronic Random Number Indicator Equipment" – is the name for a series of
hardware random number generators developed for this application. There have been five models of ERNIE to date. All of them have generated
true random numbers derived from random
statistical fluctuations in a variety of physical processes.
The first ERNIE was built at the
Post Office Research Station
The Post Office Research Station was first established as a separate section of the General Post Office in 1909.
In 1921, the Research Station moved to Dollis Hill, north west London, initially in ex-army huts.
The main permanent buildings at ...
by a team led by Sidney Broadhurst. The designers were
Tommy Flowers
Thomas Harold Flowers Order of the British Empire, MBE (22 December 1905 – 28 October 1998) was an English engineer with the British General Post Office. During World War II, Flowers designed and built Colossus computer, Colossus, the world's ...
and
Harry Fensom and it derives from
Colossus, one of the world's first digital computers.
It was introduced in 1957,
with the first draw on 1 June, and generated bond numbers from the
signal noise created by
neon gas discharge tubes. ERNIE 1 is in the collections of the
Science Museum
A science museum is a museum devoted primarily to science. Older science museums tended to concentrate on static displays of objects related to natural history, paleontology, geology, Industry (manufacturing), industry and Outline of industrial ...
in London and was on display between 2008 and 2015.
ERNIE 2 replaced the first ERNIE in 1972.
ERNIE 3 in 1988 was the size of a personal computer;
at the end of its life it took five and a half hours to complete its monthly draw.
In August 2004, ERNIE 4 was brought into service in anticipation of an increase in prizes each month from September 2004.
Developed by
LogicaCMG, it was 500 times faster than the original and generated a million numbers an hour; these were checked against a list of valid bonds. By comparison, the original ERNIE generated 2,000 numbers an hour and was the size of a van.
ERNIE 4 used
thermal noise
A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...
in transistors as its source of randomness to generate true random numbers. ERNIE's output was independently tested each month by the
Government Actuary's Department
The Government Actuary's Department (GAD) provides actuarial solutions including risk analysis, modelling and advice to support the UK public sector. It is a department of the Government of the United Kingdom.
History
In 1912 the Government ap ...
, the draw being valid only if it was certified to be statistically consistent with randomness. At the end of its life it was moved to Bletchley Park's
National Museum of Computing
The National Museum of Computing is a UK-based museum that is dedicated to collecting and restoring History of computing hardware, historic computer systems, and is home to the world's largest collection of working historic computers. The muse ...
.
ERNIE 5, the latest model, was brought into service in March 2019, and is a
quantum random number generator built by
ID Quantique. It uses quantum technology to produce random numbers through light, replacing the former 'thermal noise' method. Running at speeds 21,000 times faster than the first ERNIE, it can produce 3 million winners in just 12 minutes each month.
In popular culture
ERNIE, anthropomorphised in early advertising, receives
Valentine cards, Christmas cards and letters from the public.
It is the subject of the song "E.R.N.I.E." by
Madness, from the 1980 album
''Absolutely''. It is also referenced by
Jethro Tull in their album ''
Thick as a Brick''.
In other countries

Premium Bonds under various names exist or have existed in various countries. Similar programmes to UK Premium Bonds include:
* In the Republic of Ireland,
Prize Bonds have been running since early 1957.
* In Sweden,
Premieobligationer (lit. ''Premium bonds'') usually run for five years and are traded on Nasdaq OMX Stockholm. The unit (one Bond) is generally 1000 SEK or 5000 SEK. Holders of 10 or 50 consecutive bonds starting at 1 + N * 10 or 50 are guaranteed one win per year. Outstanding bonds were around 28.9 billion SEK.
* In Denmark,
Præmieobligation (lit. ''Premium bonds'') usually ran for five or 10 years with a fixed prize list printed on the physical bonds. They were physical bearer bonds and most series were extended one or more times by another 5 or 10 years. The last series have now ended and must be redeemed for their principal cash within 10 years of the final ending dates. The bonds were generally identified by their colour, for instance the blue premium bonds were issued in 1948, and were redeemed in 1998 (10 years + 4 10-year extension). The first 200 DKK of each prize was tax free, the rest taxed at only 15% (compared to 30% or more for ordinary income).
* In New Zealand, "Bonus Bonds" were established by the NZ Government in 1970 and sold to ANZ Bank in 1990. In August 2020 it was announced that the scheme would close due to low interest rates reducing the prize pool. At the time of the announcement there were 1.2m bondholders with NZD $3.2 billion invested.
Unrelated concepts
In 2023, American economist
Paul Krugman
Paul Robin Krugman ( ; born February 28, 1953) is an American New Keynesian economics, New Keynesian economist who is the Distinguished Professor of Economics at the CUNY Graduate Center, Graduate Center of the City University of New York. He ...
used the name "premium bonds" for an unrelated type of bond that he proposed to avoid a default due to the
United States debt ceiling
In the United States, the debt ceiling is a law limiting the National debt of the United States, total amount of money the federal government can borrow.
Since the federal government has consistently run a Deficit spending, budget deficit since ...
.
Academic studies
In 2008, two financial economists, Lobe and Hoelzl, analysed the main driving factors for the immense marketing success of Premium Bonds. One in three Britons invest in Premium Bonds. The thrill of gambling is significantly boosted by enhancing the
skewness
In probability theory and statistics, skewness is a measure of the asymmetry of the probability distribution of a real-valued random variable about its mean. The skewness value can be positive, zero, negative, or undefined.
For a unimodal ...
of the prize distribution. However, using data collected over the past fifty years, they found that the bond bears relatively low risk compared to many other investments.
Aaron Brown discusses in a 2006 book Premium Bonds in comparison with
equity-linked, commodity-linked and other "added risk" bonds.
[ Aaron Brown, ''The Poker Face of Wall Street'', John Wiley & Sons, 2006.] His conclusion is that it makes little difference, either to a retail investor or from a theoretical finance perspective, whether the added risk comes from a random number generator or from fluctuations in financial markets.
See also
*
Prize-linked savings accounts are savings accounts which use a similar system to grant interest
References
{{Reflist
External links
National Savings & Investments websiteAre Premium Bonds worth it?– BBC News, 2006
Q&A: Premium Bonds– ''The Guardian'', 2006
Companies based in Blackpool
Companies based in Glasgow
Borough of Fylde
Government bonds issued by the United Kingdom
1956 introductions
Personal finance
Public finance of the United Kingdom
Lotteries in the United Kingdom
History of computing in the United Kingdom
Tax-advantaged savings plans in the United Kingdom