This is a summary of different ways to get cash when other forms of payment are not available for you to use, like buying low cost items at a shop or post office, paying a tradesman or repairer who cannot accept cards or non-guaranteed cheques for payment and a wheel clamping operator who wants cash or because you have a prepaid or other unacceptable card. If you have enough in your account to pay for things until payday, you could use a UK debit card to pay in shops and stores offering cashback by making purchases totalling more than the store's minimum amount and asking for £10 to £50 cash in units of £10 and the checkout operator can give you the notes and charge the whole amount to your card account.
If you do not have enough money in your account then consider these options- arrange to withdraw some cash from electronic accounts like prepaid cards and consider bank transfers out from PayPal and similar services and from any web services affinity accounts you have; ask your energy supplier to send a refund to your account if you have more than £40 credit in your gas and electricity accounts, noting that some suppliers can send only a cheque; use some points in a credit card or loyalty points scheme to buy vouchers or goods and use valid vouchers you already have and put the cash you have available to other uses; use a credit card to get cash from an ATM or cash machine displaying your card scheme logo, typically costing around £4.20 to £5.30 for a £100 advance and around £14 to £17 for £300, these examples include charges and a full month interest; consider a short term loan from a credit broker on the high street or using the web and usually at higher rates; finally, consider an emergency or payday loan with around £4 to £25 added to £100 borrowed and later all paid by you to the lender within 3 to 30 days, equivalent to 1737 APR or more.