I WAS lucky enough to go to two residential school trips. The first was a PGL week in Wales in my final year of primary school. We stayed in an old bunkhouse, in our own sleeping bags (there were no duvets), and spent our days getting wet and mucky. Kayaking, caving, rock-climbing and abseiling. The trip had cost around £100. In the 90s, that wasn’t such a small sum – especially for a single-parent family – but my mum and all of the other parents found the money so the whole class could go.

The second was a three-day trip to Aberfoyle, my resounding memory of which being one boy getting a burn in the steam room and having to pull a non-swimmer classmate out of the water. There were plenty of other trips on offer, but for the most part, I didn’t even bother asking. I had as much chance of taking skiing lessons and joining the annual sojourn to the Alps with friends as I did of striking oil in the backyard. The prospect itself was inherently ridiculous. I didn’t even have a passport.

Even as a teenager I thought the sum ludicrous and entirely beyond the realms of possibility. My mum had enough to worry about without having to say no to me and explain why our finances wouldn’t stretch to a week of fresh powder and fondue in Val-d’Isere. I thought I’d spare her the trouble and binned the letters.

These days word of school goings-on are not restricted to the reliability of a child delivering it. We have ParentPay, emails and texts. We even have a school app. At least with a letter, you can digest the information and then promptly throw it away if the content doesn’t apply to you. These days there’s no escaping the constant reminder that you owe the school more money. It’s entirely different to log on to pay for your child’s meals (the school is cashless) and then see outstanding items in red, even if you’re opting out of the excursion. My daughter started high school in August. The balance for school trips is £2016.50.

There’s a week of local day trips to trampoline parks, crazy golf, the cinema and Camera Obscura, totalling £50. Then there’s a three-night trip to London with workshops at a top dance studio, a trip to London Dungeons and a West End show, for £485. The one that elicited an audible profanity was the four nights in New York. Each child can enjoy a guided Tour of TV and movie locations, a Broadway workshop, a visit to the Empire State Building, a boat tour, a walking tour of downtown Manhattan, a behind-the-scenes tour of Macy’s, and entrance to Madame Tussauds – for £1485.

Seriously? That money is a family holiday. That money is a car. That money is a boiler that stops working. That money is all Christmas and birthdays combined. For many, that money is the difference between just scraping by and poverty.

The thought of at least five more years of this, and siblings coming up behind her makes me queasy. Even if your finances are in rude health, this is not the sort of cost that can be absorbed without consideration. What’s more is I know there will be many families for whom any of these trips would be laughable. Our high school’s catchment area straddles affluent suburbs and some of the poorest areas of our city. On the Scottish Index of Multiple Deprivation (charting income, employment, health, education, housing and crime) the line runs almost through the centre of the school, with the least deprived areas in dark blue in one half, and the most deprived in red on the other. I’d bet if you drew a line down the middle of those who can go to New York and those who can’t, it would match.

High school has the opportunity to be a leveller here, regardless of where a child went to primary. A good school that covers both areas allows children from the most deprived area in the catchment to access the same opportunities and quality of education as those from the least. But these extra trips, these nice-to-haves risk pushing families on the margins further into debt.

The school, of course, say the trips are optional, but saying so is ignorant of the intense social pressure to conform that exists. No child wants to be the kid that can’t afford to go, the one who is absorbed into other teachers’ classes while the rest of your mates are going up the Empire State building. No parent can choose to put them in that situation without feeling like a failure.

Even with healthy self-esteem, being a teenager is hard enough without the added pressure of being publicly poor. Not having the money feels like drawing a target on your child’s forehead.

These trips are divisive. Pretending that these are “optional” and without consequence for those that can’t go is shameful. Every child should have the same opportunities during their education, including the cultural ones. Schools have to face the truth: these optional extras are lifelong memories for one group of pupils and a reminder of unshakable social exclusion for others.