ILM level 3, 5 or 7 probably worth a look depending on your budget and level you work at. level 3 is supervisor level, 5 manager, 7 aimed at those coaching in an exec context. there are loads of providers around the country as this is a nationally recognised standard. whichever you choose-, make sure it's not online only. coach training needs you to practice and be observed face to face. I say this as an exec coach & coach supervisor who trains coaches.

Suki Would be very happy to have a conversation and share my experience of the market. I am a coach and had training with a number of providers both ILM and postgraduate level. Feel free to connect with me on Linked In and can make time to talk so I can give you some recommendations to explore