On 16 October 1788 he succeeded Sir Robert Taylor as architect and surveyor to the Bank of England.
He would work at the bank for the next 45 years, resigning in 1833.
Given Soane's youth and relative inexperience, his appointment was down to the influence of William Pitt, who was then the Prime Minister and his friend from the Grand Tour, Richard Bosanquet whose brother was Samuel Bosanquet, Director and later Governor of the Bank of England.
His salary was set at 5% of the cost of any building works at the Bank, paid every six months.
Soane would virtually rebuild the entire bank, and vastly extend it.
The five main banking halls were based on the same basic layout, starting with the Bank Stock Office of 1791–96, consists of a rectangular room, the centre with a large lantern light supported by piers and pendentives, then the four corners of the rectangle have low vaulted spaces, and in the centre of each side compartments rising to the height of the arches supporting the central lantern, the room is vaulted in brick and windows are iron framed to ensure the rooms are as fire proof as possible.

His work at the bank was:
Erection of Barracks for the Bank Guards and rooms for the Governor, officers and servants of the Bank (1790).

Between 1789 and February 1791 Soane oversaw acquisition of land northwards along Princes Street.

The erection of the outer wall along the newly acquired land (1791).

Erection of the Bank Stock Office the first of his major interiors at the bank, with its fire proof brick vault (1791–96).

The erection of The Four Percent Office (replacing Robert Taylor's room) (1793).

The erection of the Rotunda (replacing Robert Taylor's rotunda) (1794).

The erection of the Three Percent Consols Transfer Office (1797–99).

Acquisition of more land to the north along Bartholomew Lane, Lothbury and Prince's Street (1792).

Erection of outer wall along the north-east corner of the site, including an entrance arch for carriage (1794–98).

Erection of houses for the Chief Accountant and his deputy (1797).

The erection of the Lothbury Court within the new gate, leading to the inner courtyard used to receive Bullion (1797–1800).

Extension of the Bank to the north-west, the exterior wall was extended around the junction of Lothbury and Princes Street, forming the 'Tivoli Corner' which is based on the Temple of Vesta, Tivoli that Soane had visited and much admired, halfway down Princes street he created the Doric Vestibule as a minor entrance to the building and within two new courtyards that were surrounded by the rooms he built in 1790 and new rooms including printing offices for banknotes, the £5 Note Office and new offices for the Accountants, the Bullion Office off the Lothbury Court (1800–1808).

Rebuilding of the vestibule and entrance from Bartholmew Lane (1814–1818).

The rebuilding of Robert Taylor's 3 Percent Consols Transfer Office and 3 Percent Consols Warrant Office and completion of the exterior wall around the south-east and south-west boundaries including the main-entrance in the centre of Threadneedle Street (1818–1827).

In 1807 Soane designed New Bank Buildings on Princes Street for the Bank, consisting of a terrace of five mercantile residences, which were then leased to prominent city firms.

The Bank being Soane's most famous work, Sir Herbert Baker's rebuilding of the Bank, demolishing most of Soane's earlier building was described by Nikolaus Pevsner as "the greatest architectural crime, in the City of London, of the twentieth century".
On 16 October 1788 he succeeded Sir Robert Taylor as architect and surveyor to the Bank of England. He would work at the bank for the next 45 years, resigning in 1833. Given Soane's youth and relative inexperience, his appointment was down to the influence of William Pitt, who was then the Prime Minister and his friend from the Grand Tour, Richard Bosanquet whose brother was Samuel Bosanquet, Director and later Governor of the Bank of England. His salary was set at 5% of the cost of any building works at the Bank, paid every six months. Soane would virtually rebuild the entire bank, and vastly extend it. The five main banking halls were based on the same basic layout, starting with the Bank Stock Office of 1791–96, consists of a rectangular room, the centre with a large lantern light supported by piers and pendentives, then the four corners of the rectangle have low vaulted spaces, and in the centre of each side compartments rising to the height of the arches supporting the central lantern, the room is vaulted in brick and windows are iron framed to ensure the rooms are as fire proof as possible. 
His work at the bank was:
Erection of Barracks for the Bank Guards and rooms for the Governor, officers and servants of the Bank (1790).
Between 1789 and February 1791 Soane oversaw acquisition of land northwards along Princes Street.
The erection of the outer wall along the newly acquired land (1791).
Erection of the Bank Stock Office the first of his major interiors at the bank, with its fire proof brick vault (1791–96).
The erection of The Four Percent Office (replacing Robert Taylor's room) (1793).
The erection of the Rotunda (replacing Robert Taylor's rotunda) (1794).
The erection of the Three Percent Consols Transfer Office (1797–99).
Acquisition of more land to the north along Bartholomew Lane, Lothbury and Prince's Street (1792).
Erection of outer wall along the north-east corner of the site, including an entrance arch for carriage (1794–98).
Erection of houses for the Chief Accountant and his deputy (1797).
The erection of the Lothbury Court within the new gate, leading to the inner courtyard used to receive Bullion (1797–1800).
Extension of the Bank to the north-west, the exterior wall was extended around the junction of Lothbury and Princes Street, forming the 'Tivoli Corner' which is based on the Temple of Vesta, Tivoli that Soane had visited and much admired, halfway down Princes street he created the Doric Vestibule as a minor entrance to the building and within two new courtyards that were surrounded by the rooms he built in 1790 and new rooms including printing offices for banknotes, the £5 Note Office and new offices for the Accountants, the Bullion Office off the Lothbury Court (1800–1808).
Rebuilding of the vestibule and entrance from Bartholmew Lane (1814–1818).
The rebuilding of Robert Taylor's 3 Percent Consols Transfer Office and 3 Percent Consols Warrant Office and completion of the exterior wall around the south-east and south-west boundaries including the main-entrance in the centre of Threadneedle Street (1818–1827).
In 1807 Soane designed New Bank Buildings on Princes Street for the Bank, consisting of a terrace of five mercantile residences, which were then leased to prominent city firms.
The Bank being Soane's most famous work, Sir Herbert Baker's rebuilding of the Bank, demolishing most of Soane's earlier building was described by Nikolaus Pevsner as "the greatest architectural crime, in the City of London, of the twentieth century".
John Soane