How to trademark a name in the UK: what does the process involve and is it worth doing early?

[stellapenso]

I was reading about how to trademark a name the other day and wanted to check I have understood it properly, because most of what I find is either an advert from a filing service or assumes you already have a lawyer on retainer. Here is what I have pieced together, and I would appreciate anyone correcting me.

A UK trade mark seems to be registered through the Intellectual Property Office, and it protects a name, logo or slogan for the specific goods and services you list in the application. Registration lasts ten years and can then be renewed. Applications are filed online, and the fee depends on how many classes you cover, with each additional class costing extra. I understand the whole process usually takes a few months if nobody objects, since the application is examined, published for a period in which others can oppose it, and then registered.

What I cannot work out is how much checking to do beforehand. Searching the IPO register and Companies House seems like the obvious first step, but I keep seeing advice that a name can be refused or challenged if it is too similar to an existing mark in the same class, or if it is too descriptive, for example a name that simply describes what the product is. I am also unsure about the difference between a registered mark and relying on common law rights through passing off, and whether the ® symbol can only be used once registration is complete. Another point I am unsure about is that a UK registration does not cover other countries, so a business planning to sell in the EU or the US may need separate filings through the Madrid system.

My question is how founders decide when to file, whether before launch or once the brand has traction, and whether it is worth paying a trade mark attorney or doing it yourself. I would also like to know how people choose which classes to cover, what happened when someone opposed their application, and whether a missing trade mark ever came up during due diligence in a later raise. I have read something similar to this on Entrepreneur Plus, so I would like to hear from anyone who has been through it, what they found hardest, and what they would do differently.