This deals with official name and gender marker change based on my own recent experience in Scotland. I'm writing it up while it's fresh in my mind.

Disclaimer: this is entirely subjective, non-authoritative. I'm not qualified to give any sort of advice. That said, I hope this gives readers some reassurance and encouragement to carry on with the process, if that's what they want.

I hope that other people here will be able to improve on my very partial view of what's involved.

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Name change is a big part of social transition. A lot of this happens in the personal sphere as part of coming out, but there is a lot to consider when dealing with officialdom.

It takes time. Some parts are easy, others much more time-consuming. It's well worth it in the long term.

Plan ahead! Identify dependencies: for instance, passport depends on driving licence, and passport unlocks several more changes.

Look out for pinch points and traps. Proper sequencing of who gets told will minimise these risks, but be careful and aware as it can be hard work to extricate when an organization demands something you don't yet have.

The order of service for me was:

NHS - this was dealt with very straightforwardly in person with the receptionists at my local health centre. They were happy to update name and gender marker while I was at their desk.

Legal name change - In the UK, it is possible to change your name by deed poll. In Scotland, you can also go to your solicitor for them to witness you sign a Statutory Declaration. I did the latter and updated my will at the same time.

This is a one-off, permanent change, and involves a satisfying amount of declaring and renouncing. Be sure to get at least 10 notarized photocopies of this document. You'll need to send quite a few away in the post to support other changes.

Driving Licence - this was quite straightforward and well-documented. I wrote a cover letter to make clear that I wanted my gender marker changed at the same time, and sent a copy of my statutory declaration in support.

Passport - this was slightly more involved. For this they wanted statutory declaration, driving licence and a supporting letter to indicate that I wasn't going to change my mind about my gender. My first attempt at this involved a generic letter from care provider. They didn't accept this, so I went through the process of getting a Formal Diagnosis of Gender Dysphoria from the same organization's psychologist. This was accepted, but added the already long time needed to get the passport approved. Since you will not have access to either passport or driving licence for quite a while, it's worth being careful in how you time this transaction.

Bank - for personal banking, this was a matter of going to a branch with Statutory Declaration, and driving licence. Take more care with business banking as they will likely want evidence of company ownership in your new name and might be sticky if you can't provide that ahead of time.

You will likely have many things to change that I have not listed here, and there is of course a long tail of smaller changes. It's taken around 6 months to get through the big-ticket items. There have been highs, lows, pleasant surprises, and frustrations along the way. It has been absolutely worth the effort.