Sophia Money-Coutts: If I’m sending a thank you card to a friend, do I really have to address it to ‘Mrs W Butler’ as if it’s 1928?

I had just such a quandary recently. After dinner at a pal’s house, I sent a short thank you card in the post. It had been a girls’ night — women only, pizza and rosé in her garden — and my pen had hovered over the front of the envelope. It felt weird, antiquated, to stick her married name on the front — Mrs Tom So-and-So. Given that she’s a traditional sort, I did anyway. But it felt quite strange to me. Women can vote! Women can drive! Women can re-wire a plug socket!

Ok, maybe not the last one (just kidding. No letters, please). But, still, why should we continue writing to one another as if we’re mere properties of our husbands?

It depends on the friend, I reckon. Should she be a certain age (let’s say, ooh, over 50), then you’re probably safe. Anyone under that and you may land yourself in hot water. There is a Mumsnet thread on this topic that runs to 11 pages with hundreds of furious comments from women cross that they’ve been addressed by their husbands’ names. ‘Misogynistic bullsh*t’, thunders one. ‘I F**KING HATE IT!’ says another. ‘I like it, it’s traditional,’ ventures one brave soul, only for the next commenter to retort ‘so was slavery'.

So, a surprisingly controversial topic, but also one which simply requires a little common sense. Has your friend taken her husband’s name? In that case, she likely won’t mind. Maybe she’ll even appreciate it. That was the done thing for many years, after all. If she’s one of the growing number of women who hasn’t taken her husband’s name, however, (according to most recent figures, only a third of women aged between 18 and 34 say they would), then proceed with caution. If you’re writing to the couple, use both their full names on the envelope: Hermione Granger and Ron Weasley. Or just hers. Not complicated.

Sometimes, if I’ve been to stay with friends who have children for the weekend, I send a note addressed on the front to ‘Team Granger-Weasley.’ You may not be able to get away with that if you’ve been to stay with the Prince and Princess of Wales in Norfolk, or a ducal family at their great big house. But, if they’re good enough friends and you want to thank them all, I wouldn’t worry too much about formality. It’s an envelope. It goes in the bin. There are some etiquette issues worth fussing about nowadays (phone use, punctuality, how many kisses to leave at the end of a message), and there are some that you shouldn’t angst over for more than 30 seconds. This, imho, is the latter.