Why Two People Can Search the Same Product and See Different Prices

*This is a collaborative guest post

Last winter I spent the best part of an hour trying to book a cottage in Cornwall for October half term. I found one I liked, opened a second tab to check the school dates, went back, and the same three nights had gone up by eighteen pounds. I had not logged in. I had not put anything in a basket. The only thing that changed was the amount of time I had been looking.

That happens more often than most of us notice, and it is usually less sinister than it feels. Retailers and booking sites do adjust what they show based on where a visitor appears to be connecting from, and the people who measure this for a living rely on premium residential proxies to load the same page from dozens of towns at once. According to testing data published by ProxyWing, it is common for a single product page to return different prices to visitors in different regions on the same afternoon.

What actually changes the number on the screen

Four things do most of the work, and only one of them is about you personally.

• Your rough location, worked out from your IP address. This sets your currency, your delivery options and, on travel sites, quite often your starting price.
• The device you are on. Mobile and desktop visitors sometimes see different offers, partly because mobile shoppers convert differently and partly because the mobile app and the website are frequently run by different teams with different targets.
• Stock and demand at that moment. This is the honest one. If four other families are looking at the same cottage, the price genuinely moves, and it moves back down again when they stop looking.
• Whether the site recognises you. A returning visitor with a full basket history is treated differently from someone arriving cold.

The first of those is the one worth knowing about, because it is the only one you can check yourself in about two minutes.

The part that surprises people most

It is not the price rise. It is the currency. A lot of sites decide which storefront to show you before you have clicked anything, and the exchange rate they apply is their own, not the one your bank would give you. I have seen the same pair of children’s trainers listed at 34 pounds on the UK store and the euro equivalent of about 31 on another, with free delivery on both.

If you shop across borders at all, that gap is worth more than most cashback schemes. It is also completely invisible unless you go looking, because the site will keep putting you back on the UK storefront every time you return.

Subscriptions are where this really adds up

One off purchases are annoying. Subscriptions are expensive, because the difference repeats every month for years. Streaming services, music, cloud storage, photo editing software and most of the apps that quietly renew on a family account are all priced by region, and the gaps are not small.

The important thing here is that your subscription price was set when you signed up and in the country you signed up from. Moving house does not change it. Moving country usually does not change it either, at least not until the card on the account expires and you have to re enter payment details. That is the moment a lot of people discover they have been paying an old rate, sometimes a better one.

Before you let anything auto renew, it is worth opening the pricing page in a private window and seeing what a new customer is quoted today. Twice now I have found that the new customer offer was cheaper than my loyal renewal, and both times a short message to support moved me onto it.

How to check it yourself

You do not need anything technical. Open the product page as normal, note the price, then open the same page in a private browsing window. If the number moves, the site is reacting to something it knows about your session. If it stays put but the currency changes when you switch to the .com or .de version of the site, you are looking at regional pricing rather than personalised pricing.

There is a second check worth doing on bigger purchases. Open the page on your phone using mobile data, with the house wifi turned off. Your phone on a mobile network looks like a completely different visitor to the site than your laptop at home does. If the two disagree, you have found a site that prices by session, and the cheaper of the two is the one to buy on.

Do it once on something you were going to buy anyway. It takes a minute and it tells you whether a particular retailer is worth the extra checking for the rest of the year.

What tends to vary, and by how much

Type of purchase	How much prices tend to move by region	Worth checking?
Flights and hotels	Frequently, sometimes 10 to 20 percent	Yes, every time
Car hire	Frequently, and the insurance add ons vary more than the base rate	Yes
Clothing and shoes	Occasionally, mostly through currency and delivery	Worth a look on larger orders
Groceries and household	Rarely	No
Digital subscriptions	Very often, and legitimately so	Yes, before you renew
Event and attraction tickets	Sometimes, usually on resale platforms	Yes
Toys and gifts in the run up to Christmas	Sharply, but by demand rather than region	Buy early instead

What helps and what does not

Clearing cookies helps on sites that price by session and does nothing on sites that price by region. Browsing in a private window is the same thing with fewer steps. Signing out of your account is worth doing on travel sites and pointless on retail ones.

What does not help is the advice you see repeated everywhere about booking flights on a Tuesday. That was true for a period around a decade ago and has not been true for years. Airline pricing now moves continuously and reacts to how full a specific flight is, not to the day of the week you happen to look.

Where I have landed on it

I am not going to pretend I check every purchase. Life is too short and most of what I buy is not worth the effort. But for the two or three big family bookings a year, the holiday and the flights and the occasional big ticket item, I now look twice before I click. The Cornwall cottage went back down the next morning, for what it is worth. I booked it then, from my phone, on mobile data, which may or may not have been the reason.

FAQ

Is it legal for shops to show me a different price than someone else?

In the UK and EU, yes, within limits. Retailers must be clear about the final price including delivery, and they cannot discriminate on nationality alone for most goods and services. Varying by region, demand or device is allowed.

Does clearing my cookies bring the price back down?

Sometimes, on sites that price by session history. It does nothing on sites that price by region, because your location comes from your connection rather than from anything stored in the browser.

Is a VPN the answer?

It changes your apparent country, which is enough to see a different storefront. It will not usually get you a cheaper checkout, because payment and delivery details still have to match a real address.

Should I worry that sites know where I am?

Not especially. Approximate location from an IP address is how a site knows to show you prices in pounds and delivery times in days rather than weeks. It is far less precise than the location your phone apps have.

Does any of this apply to the supermarket shop?

Barely. Grocery pricing is set by store and delivery area rather than by browsing behaviour, and the variation you see between slots is about capacity, not about you.