Have you talked to your endo or diabetes nurse to let them know you'd like to have your hba1c checked more often than once a year?Is there a private health group (favoured by contributors here) that will check my HBA1C every three months, rather than letting me wait for the NHS annual check?
As far as I know, the NHS guidelines say every 3 months unless there's a reason not to. (I'm not in the UK but our guidelines are very similar. I only do once a year by choice, but this took a bit of work convincing my endo who'd prefer every three months or at least twice a year.)
Do you use a CGM? For me, the predicted hba1c isn't very accurate, but I find it a wonderful tool to see where I can adjust things.
As for having your hba1c checked privately, there are home tests available which you send to a lab.
I have no experience with these but I'll tag @AndBreathe for you, who has used them.
There must be a couple of threads on home tests as well but I can't find them. AndBreathe hasn't been around a lot lately, maybe @Rachox knows about them?