Here's some UK blood test providers I've been jotting down in my notes:
Medichecks: I think Medichecks is the most popular provider, and they have hundreds of tests. They have at-home test kits (fingerprick, swabs, saliva, urine, stool), in-clinic blood draws, and hard-to-find things like STD and drug tests. I signed up for their referral program, so I get 10% if you use my link, and you get a 10% discount using the code MEDUK10.
Blue Horizon Medicals: I think this is the second most popular provider, focused mostly on in-hospital blood draws. They initially confused me because they're split into four different sites and services. It looks like you'd want to filter them this way:
If you're in London with convenient access to their 76 Wimpole Street location, visit bloodtestslondon.com to order online.
If you're in their locations with a BMI hospital (Aberdeen, Bath, Beckenham, Birmingham, Blackburn, Blackheath, Bolton, Brentford, Canterbury, Cheadle, City Of London, Croydon, Dartford, Dorchester, Edgbaston, Enfield, Great Missenden, Harrow, Hendon, Huddersfield, Maidstone, Northwood, Nottingham, Orpington, Princes Risborough, Rochdale, Sheffield, Stepney Green, Stirling, Swindon, Windsor, Worcester), visit privatebloodtests.com. You'll order online and attend the BMI hospital location for the blood draw.
If you're in their locations with a Spire hospital (Birmingham, Brentwood, Brighton, Bristol, Cambridge, Cardiff, Chatham, Edinburgh, Harpenden, Horley, Hull, Leeds, Leicester, Liverpool, Manchester, Norwich, Portsmouth, Reading, Slough, Southampton, Southend On Sea, Tunbridge Wells, Warrington, Washington, Watford, Wirral, or Wrexham), visit privatebloodtests.co.uk. You'll order online and attend the Spire hospital location for the blood draw.
In other locations, bluehorizonmedicals.co.uk can mail you an at-home testing kit, arrange a nurse to come draw the blood, or provide a kit for you to arrange your own phlebotomy service to draw the blood.