The attached spreadsheet presents the cost of naturalisation across the past 50 years in today’s prices. The inflation adjustment allows real-terms comparison of costs from 1975 to 2024.

What is naturalisation?

Naturalisation is the main legal process by which adults can gain British citizenship. The Home Secretary’s power to grant naturalisation to foreign residents prepared to offer an oath of allegiance and pay the appropriate fee began with the Aliens Act 1844.

In modern times, ministerial power to create naturalised citizens comes from section 6 of the British Nationality Act 1981, and the power to charge fees from section 68 of the Immigration Act 2014. Most people become eligible for naturalisation a year after achieving permanent residence, which itself normally takes five years.

How much does naturalisation cost?

In 2024, the naturalisation charge for applicants is £1,580 (including the £80 cost of a citizenship ceremony).

This compares to the £505 ‘unit cost’ of naturalisation—the estimated expense incurred by the Home Office in providing the service. The surplus is used to cross-subsidise other areas of the UK immigration system.

The Government has said that fees are set in line with the considerations allowed by the 2014 act, “which include the cost of processing the application, the wider costs of running the Migration and Borders system and the benefits enjoyed by a successful application”.

What costs aren’t considered here?

The attached document collates the main fee for naturalisation and the additional charge for the mandatory oath of allegiance, which since 2004 has been taken at a citizenship ceremony. A small administration fee was added from 1984 to 1990.

Fees for biometric enrolment, Life in the UK test and English language test (where necessary) are not included. The total cost of the naturalisation process is therefore likely to have been slightly higher for many people.

Conversely, costs will have been lower for people married to a British citizen from 1981 to 2005 (under section 6(2) of the British Nationality Act 1981). This reduction was particularly significant from 1981 to 1990. For example, the default section 6(1) naturalisation fee in 1983 was £200 whilst the section 6(2) fee for the spouse of a British citizen was £70.

These costs relate only to the naturalisation process itself and do not capture the other fees incurred while passing through the immigration system (for visas, extensions, permanent residence and ancillary charges).



Prior to 1983, naturalisation was covered by the British Nationality Act 1948 and the terminology ‘aliens’ used to describe those applying for naturalisation. This is reflected in the data table entries for 1975 to 1983.

The 1981 British Nationality Act 1981 came into force in January 1983. Naturalisation of non-spouses from 1983 onwards falls under section 6(1) of that act (marked as s6(1) in the data table).


The sources used draw in turn from underlying secondary legislation. They appear accurate but if there is any conflict, the legislation will prevail.

Real-terms adjustment

Costs are adjusted using Treasury GDP deflators, December 2023. The GDP deflator for 2023 and 2024 is calculated using the Office for Budget Responsibility forecasted measure of inflation as a percentage increase.

Further reading

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