Parcel Monkey, choose DHL and they’ll do 13Kg for £8.58 collected from your door and delivered next working day.
https://www.parcelmonkey.co.uk/
Also a lot cheaper for extra insurance cover for more valuable items if you need it, for coverage up to £100 it’s only £1.29 (+Vat) extra. It’s a sliding scale so just put your parcels value in and it adjusts automatically.
Have used them several times without a problem.
Please excuse spelling/typos. Apart from being a clot it turns out I had one on my cerebellum that's now causing various problems!