A Bank of England Ten Shilling note (Series C - red/brown)(Chief Cashier L.K. O'Brien - serial H90), uncirculated and in absolute mint condition could fetch anything £10 GBP. If it has been circulated but still in good condition, it might fetch anything from £2 to £8 GBP.
A reputable coin dealer will be able to give a more accurate valuation.
I have no way of knowing whether or not it was circulated, but the serial number of the last Bank of England Ten Shilling note commenced with D38N and possibly ended with 999999.
Bank of England Ten Shilling notes issued from October 1961 had a serial number format of LNN (letter, number, number) followed by 6 digits, eg. A01 123456. Serial numbers for this period commenced with the following letters - A, B, C, D, E, H, J and K. Replacement notes commenced with M and used the range M01 to M18. These serial ranges may have extended into 1962.
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.
Please check the serial number and provide the name of the Chief Cashier if possible.
It is worth 5 pence if you mean the English shilling
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 Ten Shilling note (Series C - red/brown)(Chief Cashier J.Q. Hollom - serial 26H), uncirculated and in absolute mint condition could fetch anything £8 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 L.K. O'Brien - serial A12), uncirculated and in absolute mint condition could fetch anything £12 GBP. If it has been circulated but still in good condition, it might fetch anything from £3 to £9 GBP. A reputable coin dealer will be able to give a more accurate valuation.
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.
It is difficult to tell. What country is it from and whose signature is on it?
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.
A Bank of England Ten Shilling note (Series C - red/brown)(Chief Cashier J.S. Fforde - serial 70S), uncirculated and in absolute mint condition could fetch anything up to £14 GBP. If it has been circulated but still in good condition, it might fetch anything from £2 to £6 GBP. A reputable coin dealer will be able to give a more accurate valuation.