'Sundries and Emergencies' allowance is max. £12 per adult (£23 for a couple), £11 per child.
If you are struggling, are you claiming for all the allowances that you are able to?
The Stepchange Budget guidelines make allowances for 'essentials' such as: Meals at work, hairdressing, newspapers/magazines, sports/hobbies, kids pocket money etc. as well. Many people don't consider these, yet they can amount to £60-£70 per month per person (only if applicable of course).
Worth having a look at the guidelines: Make sure you are claiming all the allowances that apply to you, and this may help you get by a little better each Month.
My opinions are just that: Based on my experience and being a self-employed IVA customer.
Budgeting and allowances are usually better based on what you actually need to spend, rather than what someone tells you that you are allowed to spend. Why not ask your IP to do a review of your current situation to see if they can allow you any more leeway based on your own figures.