If your Ten Shilling note has Queen Elizabeth II on the obverse and a large image of a seated left facing Britannia on the reverse, a serial number commencing with S74 would be Chief Cashier J.Q. Hollom, possibly printed in 1963.
The Chief Cashier would be K.O Peppiatt (1934 to 1949).
Please check the serial number and provide the name of the Chief Cashier if possible.
A Bank of England Ten Shilling note (Series C - red/brown)(Chief Cashier L.K. O'Brien - serial T41), circulated but still in good condition, might fetch anything from £2 to £8 GBP. A reputable coin dealer will be able to give a more accurate valuation.
Without additional context, the value of a Bank of England Ten shilling note with serial number 18Y 015906 would depend on factors such as its condition, rarity, and demand among collectors. I recommend consulting with a currency appraiser or a numismatic expert for a precise valuation.
A Bank of England 1940? Ten Shilling note (Series A - red/brown)(Chief Cashier K.O. Peppiatt - serial E53D), uncirculated and in absolute mint condition could fetch anything up to £65 GBP. If it has been circulated but still in good condition, it might fetch anything from £20 to £34 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A Bank of England Ten Shilling note (Series A - red/brown)(Chief Cashier L.K. O'Brien - serial number B15Y), uncirculated and in absolute mint condition could fetch anything up to £40 GBP. If it has been circulated but still in good condition, it might fetch anything from £10 to £18 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A Bank of England 194? Ten Shilling note (Series A - red/brown)(Chief Cashier K.O. Peppiatt - serial J19D), uncirculated and in absolute mint condition could fetch anything up to £80 GBP. If it has been circulated but still in good condition, it might fetch anything from £30 to £65 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A Bank of England 193? Ten Shilling note (Series A - red/brown)(Chief Cashier B. G. Catterns - serial V99 281094), uncirculated and in absolute mint condition could fetch anything up to £320 GBP. If it has been circulated but still in good condition, it might fetch anything from £80 to £200 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A Bank of England Ten Shilling note (Series A - red/brown)(Chief Cashier K O Peppiatt - serial 08I), uncirculated and in absolute mint condition could fetch anything up to £170 GBP. If it has been circulated but still in good condition, it might fetch anything from £30 to £70 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A Bank of England 1967(?) Ten Shilling note (Series C - red/brown)(Chief Cashier J.S. Fforde - serial D__N), uncirculated and in absolute mint condition could fetch anything up to £10 GBP. If it has been circulated but still in good condition, it might fetch anything up to £4 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A Bank of England Ten Shilling note (Series C - red/brown)(Chief Cashier J.Q. Hollom - serial Z15), uncirculated and in absolute mint condition could fetch anything up to £16 GBP. If it has been circulated but still in good condition, it might fetch anything up to £8 GBP. A reputable coin dealer will be able to give a more accurate valuation.
A Bank of England Ten Shilling note (Series C - red/brown)(Chief Cashier J.S. Fforde - serial C89N), uncirculated and in absolute mint condition could fetch anything up to £10 GBP. If it has been circulated, not much. A reputable coin dealer will be able to give a more accurate valuation.
a very rare banknote, worth upwards of £10000