I always enjoy the discussion of the headline but never the detail...the £1600 replaces every benefit including state pension bar housing benefit uplift ie rent over the rent act and child/disability payments...the cost of the dwp is roughly 1/5 of the total benefit bill, or 12.2 Billion a year, HMRC add another 12.7 billion in costs. The point of this is that both the underlying costs are slashed and the tax code is simplified. Basically you pay 20% on everything over the UB amount upto 100k and UB is reduced until 150k and then you don't get UB but then pay 40% on everything above.
most reliefs are scrapped..it means that top earners pay roughly 42% on everything and upto 150k people pay 31%, under 100k pay 25%, under 50 its 20%....But that means all income is taxed as income...no more stuffing a pension etc
Basically is designed to replace virtually all benefits and tax thresholds..if you just think about the benefit limits - job seekers for example 84.50 a week - but costs £49 a week to administer, if you take any work then JSA stops and you have to make a universal credit claim....
In the UB world, none of that applies..no UC, JSA etc etc. you need extra money then you can take any job no silly tapers nothing just 20% on whatever you earn..