I'm not a single parent, but I’d like to travel as one. It’s a shame it’s so expensive.

My husband ran out of annual leave recently. It happens annually.

He takes the Easter and summer holidays off, and the rest of the 13 weeks of school holiday I manage alone at home trying desperately to fill time with activities for a five-year-old without siblings. Being a freelance writer makes this possible for me.

But this year, I thought, why not actually enjoy it? Why does the fun have to be saved for a ‘full’ family event? We could do something together, just the two of us, we could go away somewhere.

Learning of Lily Allen’s solo parent trip got me excited about the idea. She had taken her two daughters on a chic-looking holiday to Palm Heights Grand Cayman, a five-star resort in the Cayman Islands with rooms from more than £755 a night, where fellow guests comprised actresses, models and, of course, simply the well-to-do.

It looked amazing. And how cool to take your daughters on a girls-only trip? Yes, I’m married, but I could do that too (at least, so I thought).

OK, perhaps I couldn’t afford something quite as luxe as the Cayman Islands. But maybe I could stretch to a standard, sunny, package deal. 

Playing mermaids in the pool and card games after dinner. Lying on sunbeds with ice creams. Going on short coach excursions, packing snacks. I was not looking to brush shoulders with celebs.

But what shocked me was discovering that travelling with one adult instead of two doesn’t make the holiday cheaper. 

When I Googled trips, I found prices were working out exactly the same whether I added my husband to the trip or not. How on earth do single parents manage it?

Because ‘family’ deals only apply to two adults; travelling as one adult and one child means you lose the free child place. And prices are already hiked up because it’s half term.

Which begs the obvious question: why is a five-year-old being priced like a grown adult? 

She isn’t drinking endless cocktails by the pool at all-inclusive hotels, polishing off bottles of wine at dinner or emptying the minibar. She’ll only eat plain pasta from the buffet and a self‑serve juice from a machine. It’s so infuriating.

The problem is the industry has decided two parents is the basis of a ‘full’ family: that’s what they should look like, and that’s how they will be charged. If you’re planning a trip as the only adult, you simply have to pay extra.

Sure, the industry has come at least some way (though not far enough) in providing discounted rooms for solo travellers. Why not for single parents?

There are more than three million lone-parent families in the UK. Then there are those like mine, with two parents but who cannot always travel that way because of the mismatch between the school holidays and annual leave.

Families today look different than when package trips were first created last century. It’s about time the travel industry caught up.