The £15k is worth £8700, I believe, or £725 per month. The 40% higher rate tax takes £6000, but the extra National Insurance contribution is just £300 (it is o

The £15k is worth £8700, I believe, or £725 per month. The 40% higher rate tax takes £6000, but the extra National Insurance contribution is just £300 (it is only 2% on earnings above £797 per week).