The chancellor's speech usually starts at about 12:30 UK time and lasts about an hour.
It will be broadcast live on the BBC iPlayer and the BBC news website.
It is likely to be the last Budget before the general election, which must be held by the end of January 2025.
National Insurance
It has been reported that the government may cut National Insurance (NI), rather than income tax rates.
Senior government figures are not denying that the chancellor plans to cut a further 2p from NI.
In the 2023 Autumn Statement, the chancellor announced a 2p NI cut for 27 million workers, which took effect in January. Self-employed NI rates are set to drop in April.
Income tax
Cutting the main rate of income tax by 1p would cost £7bn, according to the Resolution Foundation think tank.
Alternatively, the government could spend a similar amount cancelling the current freeze on the amount people can earn before they start paying tax, or higher rates.
The International Monetary Fund (IMF) and the Institute for Fiscal Studies (IFS) think tank have both warned the government about the danger of cutting taxes.
Childcare
The government has already announced an expansion of free childcare places in England, beginning in April.
But in January, the chancellor acknowledged the current child-benefit rules may be unfair.
Currently, claimants who earn more than £50,000 lose some of their family's child benefit. However, a family where two parents jointly earn more than £50,000 receives the full amount.
The chancellor may raise the income threshold.
Vaping
A UK-wide ban on disposable vapes has been announced, and the government is considering a new vaping tax as well.
Vaping products are already subject to value added tax (VAT) - but unlike tobacco, do not attract a separate levy.
Fuel duty
Fuel duty has been frozen since 2011, and this is expected to continue.
The chancellor is also expected to extend a 5p-a-litre fuel duty cut which is due to end in March 2024.
The IFS estimates that continuing the fuel duty freeze would cost £6bn in 2027-28.
Air passenger duty
The government may increase Air Passenger Duty for business class passengers.
The amount paid varies according to flight distance and ticket class.
Non-dom tax status
The government may also scrap "non-dom" tax status which is used by people who live in the UK, but whose principal home for tax purposes is elsewhere.
Non-domiciled people only pay UK tax on money earned in the UK.
Scrapping the status could raise £3.6bn a year, according to research by the London School of Economics and the University of Warwick.
Oil and gas windfall tax
A windfall tax was introduced for oil and gas companies in 2022, after energy firm profits soared following Russia's invasion of Ukraine.
The Energy Profits Levy applies to profits made from extracting UK oil and gas, and raised £2.6bn in its first year.
It is due to run until March 2028. However, reports suggest it may be extended.
Holiday lets
The government is already clamping down on holiday lets.
The Budget may include new controls in England designed to prevent local people being priced out of the housing market.
Owners may need council permission to let their home.
99% mortgages
According to reports in the Financial Times, the chancellor may introduce 99% mortgages.
This could make it easier for first-time buyers to get on the housing ladder, as they would need only a 1% deposit.
But critics have warned such a scheme could put borrowers at risk, if falling house prices meant they owed more than the value of their property.
The UK economy went into recession at the end of 2023, after shrinking for two three-month periods in a row.
However, Bank of England governor Andrew Bailey said the recession may already be over.
But even if the economy is now growing, many households are still struggling financially after two years of rising prices.
Some parts of the Budget, such as defence spending, affect the whole of the UK.
Others, such as education, only affect England.
This is because Scotland, Wales and Northern Ireland make their own decisions about some spending.
If the government announces extra spending on areas that only affect England, the other nations get an equivalent extra sum of money.
Scotland is able to set its own income tax rates, which are different from the rest of the UK.
The Scottish government set out its budget for the 2024-2025 tax year in December, and announced two tax increases from April.