Quick question about bottles & teats

[stripeyZ]

Are the different brands of bottles and teats inter-changable or do you need to by the same brand of both?

Most of them aren't interchangeable unfortunately (at least the different ones I tried)

Mam teats can be used in Avent bottles; however my dd refuses to even entertain the Avent teats, she just about manages to let me get the Mam teat in her mouth and she sucks a bit!

Thank you! V helpful