The main issue I’ve experienced with changing my name has been people who have rejected my deed poll based on an assumption that it needs to be notarised or come from an official government body like “the deed poll office” (no such government department, it’s a private company). We end up in a back and forth dance with me having to show them the actual government guidance for deed polls and how they all work.
They’re free unless you need an enrolled one.
The reason I bring this up is I’ve just had to do this again. Changed my name on an online portal, support team emails me asking for the official deed poll and I email them back with the same document and clarify the govs own directions and I’ve now received an email saying that it’s been accepted and my name has been updated.
Know your rights!