I have worked at my current occupation for coming up to 3 years now during which I have celebrated 2 birthdays, granted I was off work for both of them as I booked it as holiday. I have never received a birthday gift from my office yet have been told to contribute to other people's birthday gifts on multiple occasions. The most recent of which was just today. I have contributed to multiple birthday gifts in the past but now I'm putting my foot down.
It was my colleague's birthday this past week which she was away for but received a gift of flowers and a gift card before she left. I received an email this morning saying I owe a £5 contribution for this, to which I replied simply: “no, sorry. Not the best time.”.
I then received another email later than morning from the colleague who's birthday it had just been saying that it was another colleague's birthday tomorrow and if everyone could please chip in. I have yet to respond to this one but figure if I'm asked again I'll just simply say no.
There have been multiple occasions while in my current place of work where I have been told I owe money for people's birthday gifts, often with next to no or no advanced warning at all.
I don't think I'm being unreasonable for refusing but know I'll most likely be given the cold shoulder by at least some colleagues for doing so.