//As far as I know 40 hours is a working week.//
Depends where you look. Many people only get paid for the hours they work and not for breaks. Some careworkers do not get paid for the time it takes them to travel between their client’s premises. But even if you’re right, firstly I think your Tax and NI deductions are not quite correct. The gross pay is £19,760. Tax on that (£12,570 personal allowance), so taxable pay is £7,190, x 20% = £1,438. NI is payable on £19,760 minus £9,568 primary threshold = £10,192. At 12% = £1,223. So Total deductions are £2,661, net pay £17,099pa, £1,432 per month, £328 per week. But I may be wrong.
I purposely based my calculations on a single person. Your idea that Universal Credit should be paid to enhance the pay of people with extra expenses simply shifts part of the employer’s paybill to the taxpayer. The employee should meet all his living expenses, not the taxpayer. If he cannot do so on the minimum wage working full time then that wage is insufficient. Personally I think to expect anybody to work 40 hours for £328 is taking the pee. If you live in London or any large city (as the majority of the population does) then three hundred quid a week is subsistence level. Yes, you can scrimp and scrape and just get by and that’s what many people have to do. That’s not “living”, it’s existing hand to mouth. They cannot save for unexpected bills, they cannot contribute to a pension, they cannot take a decent holiday. They are working simply to exist. That’s not the sort of economy this country should be operating.