How do I get rid of a musty smell in my flat?

keep the dehumidifier on constantly. You will see the smell will disappear. If you are dealing with more of a moldy smell, then that dehumidifier is the key! It may take months for the smell to dissipate but it should work. AND keeping water out!! They might have to fix any issues with the gutters and adding some drainage tiles in the yard underground to carry water away from the building so you don't get any flood waters coming in which will give all the musty moldy smells. But if you are renting you might not have any control over all that. Good luck!

I'd first want to determine why I have the smell. Is there a small leak somewhere? Is it a basement flat? If everything checks out and you've thoroughly cleaned everywhere, fill a margarine container half full of vinegar and leave out for a day or so. Hopefully that will do the trick.

Thankyou ladies I appreciate it. Well the smell is more fousty in the hall and there had been a leak caused by lady up stairs, but the roof etc I've had replaced since I moved in November last year the smell isn't always there but it comes and it goes? Also I'm bottom floor flat it's a small block of another 3. I've a basic humidifier in my hall which is hidden behind a leaning mirror and I have had to empty out few times now. Also though the smell can be really fousty bad in my kitchen I don't know if I need more air vents in there as it is a very small kitchen with a built in original pantry? Just sort letting you see it's an old building but lovely any other tips would be appreciated. So I can possibly have to get someone in to have a look 🙄

I like fans, one to blow fresh air in, and one to blow stale air out, it also acts to dry out excess humidity. If you don't have 2 windows, get one of these window fans where one blows in and other out.... https://www.walmart.com/ip/Holmes-Dual-Blade-Twin-Window-Fan-White-Small-Fan-Portable-Double/742759420 You can use vertically too

or these fit in one of those windows that slide sideways real good

These work good too, I use a lot with my clients and they are cheap... https://www.walmart.com/ip/Cool-Works-10-2-Speed-Box-Fan-Model-F-1022-White/55331496

To get rid of the smell Frebreeze Air Effects kills most odors quick, and they have small plug ins too. If that doesn't work get Room Shocker at the big box home stores.

I lived in a tiny 1930s cottage, and I installed a ceiling fan to replace the ceiling light, and had a light kit added to the fan. I found a 25 inch one.

You could also buy a moisture meter, and check for leaks in the wall or ceiling.

A dehumidifier should help! It helps in my basement, and also completely fixed the musty smell at my sister's place.

Ventilation, Dehumidifiers, Silica Gel. Febreze.