To think people shouldn't just be walking into Dd's flat?

He should have knocked and the residents could have been informed better. Like via text with a time slot so she knew to be up and dressed between 8 and 12 or something.
I live in a housing association flat and that's what happens for me, I also get a text when the tradesman is on the way.

YES YOU CAN!!! And she should

“I think you'll find the vast majority of fire alarm testers are probably men so no, not really that odd at all. I think your post says more about you than it does a landlord letting a tradesman in to their property (albeit without the courtesy of knocking)”

It’s not about the landlord is it? He wasn’t the one who walked in uninvited to the DD’s flat, unless I’m reading it all wrong.
And how odd that ‘the vast majority of fire alarm testers are men’ Are they all part of the fire service? At my last place of work it could be done by any admin person, and in a school it’s usually one of the staff, isn’t it?
I can’t say I really care if my post says more about me (well, duh) — but how many of us have had a woman let herself into our house, flat etc without knocking?
And perhaps have a think about crime stats and which of the two sexes commits nearly all violent crime.

This. 🙄

Is it a uni residence? I know my boy friend at uni was always Having his fucking alarms tested that time on a sat morning was a nightmare.

No way should the landlord be giving out keys to workmen to let themselves into people's homes.
Even with notice, the tenant has the right to refuse. They should knock the door, then if no reply get the landlord to phone you.
I'm pretty sure it's illegal to just walk in.

How did he have access to her flat?

Well she'll need to check first, so no, she can't just do it.

*In most cases, a tenancy agreement will forbid tenants from changing the locks in a rental property. If they do so without the landlord's permission, it could be grounds for a Section 8 eviction. However, if the tenancy agreement doesn't expressly state that tenants can't change the locks, they are free to do so.

You can't just change the locks on someone else's property.

it's recommended to do that.
also many contrnt insurances stipulate that no keys are to be left with 3rd parties.

BULLSHIT If we hadnt changed the locks on the door of our HA flat it would have affected our contents insurance

You can't just walk into a flat someone else is renting so if the landlord knows one of these things and not the other, they are on legally shaky ground themselves!

She needs to keep her door locked at night so nobody can come in.

Does she have a room in a shared flat or rent the entire flat herself?
I ask because how she should handle it is a bit different depending on whether they were given access by a flatmate to communal areas and then went in her room or whether they let themselves in to her private flat.

(Neither are ok btw)

Yes you can as long as you change them back afterwards

A wedge would be good, too. Very effective.

Depending on the type of lease agreement the landlord can enter on reasonable notice to undertake repairs. Notice was given by the sign in reception. Whether it was reasonable or not depends on how visible it was and how long it was there.
It usually doesn't have to be reasonable if there are health and safety concerns. Emergency it can be immediate access.
He should have knocked. Maybe he did and she didn't hear so he entered. I would say 8.30am earliest acceptable time under reasonable.

Jam a chair against the door so it won't open even if they have a key.

You can't just change the locks in a flat you don't own.

Report to Police. Get locks changed and add new locks.

Oh god. I hadn't actually thought of this but now that you mention it...

I went 100% ballistic on my letting agency when I was in my late 20s and this happened. Twice. From memory, the first time was in the afternoon - I have no idea if they knocked or not as I wasn't there but they hadn't told me someone was coming in and I was therefore very confused to realise someone had been in the flat when I got home. I called to complain. They apologised. Few days later they let me know someone (same guy I think) was coming over the next day to follow up on whatever it was. I was home, awake thank god, but he also just walked in.

From memory I think I threated to sue them! But it never once occurred to me at the time that it was on purpose and now suddenly I'm realising that actually, there's a very good chance that this was opportunistic - I was a young, single woman renting a flat. I feel slightly ill.

OP - your dd should feel very comfortable going absolutely mental at her landlord or the letting agency.

https://www.landlordstudio.com/uk-blog/can-tenants-change-locks

Useful information here

No kidding.

Not quite the point, but is your DD following this up with her landlord herself? If not, why not?

Sounds like uni halls? And they always did stuff like this

She should have been adequately warned beforehand AND he should have knocked before letting himself in. Not unusual for letting agents to let themselves in or allow tradespeople access but they should always warn beforehand (although usually it's a 'we'll be here on x day, sorry can't give a time'' which is annoying but standard)