17 Costco tips – is it worth it?

• It's all about buying in bulk. Most items come in non standard sizes. The idea is it's cheaper, but not everything is – see our research below.

• You need to pay for membership. It's usually £33.60/year, so before you join, do the maths and work out if you're likely to save more than this initial outlay.

• Only certain groups are eligible. It's usually related to your line of work. We've a full list below.

This is great for larger households who buy in bulk, or those catering for big parties and barbecues. You’ll also need space to store things and most likely a car to drive your purchases home in.

Not everyone will save though. Costco often doesn’t beat supermarket own-brand prices or those at Aldi and Lidl.

We found that Costco is very competitive on brands, so could be a winner for die-hand fans of big-name products. Eg, we saw a giant block of 1kg Parmareggio cheese for £15.49, which would have cost £42 at Ocado (see picture, right).

Plus if you live near a warehouse and cover a lot of miles, you could also save £100+ on petrol costs.

You can’t just walk in and shop, you need to buy membership. In fact, membership fees are one of the main ways Costco makes money – it nets billions a year from these.

Membership is £33.60/year (trade membership is £26.40 if you can prove you run a business). This includes a card for a spouse/domestic partner.

You can sign up online or in-store, though if you sign up online, you’ll still need to pop over to the membership counter with the relevant ID. You can get in if you:

• Own your own business. You need to provide evidence, eg, VAT registration certificate, business bank card or taxi driver licence. See a full list.

• Have an occupation on its list. These include local government, banking, medicine, education or the police. See a full list.

• Are qualified in certain professions. Eg, accountant, dentist, architect or solicitor. See a full list.

• Your employer has signed up. Some firms set up access for workers. Costco doesn’t provide a list, but it could be worth asking your HR department.

Anyone can sign up for an online-only membership, however we found online prices were less competitive than in-store. There's more on online membership below.

There’s a little-known way you might be able to join if you don’t fit into the categories above. AA, RAC and National Trust members are eligible to join at certain locations.

Sadly, this doesn’t work at all stores, but I called all 29 UK Costcos and was told this worked at Birmingham, Sheffield and Cardiff. The catch is you can only shop at the location you joined at.

Costco’s press office wouldn’t give official confirmation, so it’s worth calling ahead before making a special trip. Also see how to get AA and RAC cover for less.

One of the boons of membership is access to cheap fuel and this is one of the things MoneySavers rave about. The downside is the queues are often longer than Glasto.

Go to PetrolPrices.com, enter your postcode and tell it how far you're willing to travel (five, 10 or 25 miles). It'll list that day's cheapest petrol stations in your area, covering about 8,300 forecourts across the UK.

A quick check showed Costo could save you some decent cash. For an Essex postcode, the price of unleaded within a five-mile radius ranged from the cheapest, Costco at 127.9p/litre, to a pricey 159.9p/litre. (Prices include VAT.)

For someone driving 15,000 miles a year, averaging 35 miles per gallon (12.4 km per litre), just filling a tank at the average UK price would cost £2,650 annually as of November 2024. When we checked, buying at Costco would cost £2,492, saving £158 a year.

Of course, you’ll pay a £33.60 membership fee to nab those prices. But if you clock up a lot of miles and live near a Costco, you could save big, as MoneySavers Andrew and Brett found:

While our research found Costco's price was competitive on brands, it usually won’t beat supermarket own-brands or Aldi and Lidl. And who says upmarket brands are best? The supermarkets flogging them, of course. So don’t believe the hypnosis. The downshift challenge is to TRY dropping one brand level on everything you buy. Then see if you can tell the difference. See Supermarket Shopping Tips for more.

As an example, we found two Crosta & Mollica pepperoni pizzas were two for £7.49 at Costco (the next cheapest we found for the same brand was £10). However, two Tesco own-brand pepperoni pizzas came to just £3.30. Kirkland Signature (Costco’s own-brand) ground filter coffee was £10.30/kg, whereas Aldi’s equivalent worked out at £9.70 for the same amount.

That said, if you’re a die-hard brand fan and are buying them anyway, there can be some cracking deals.

We wanted to put this to the test, pitting Costco against the supermarkets. To get an idea, we spot-checked sold prices for 30 items, from coffee to cheese and TVs to toasters.

Our analysis shows Costco had some good deals, with branded items often cheaper than rival stores, though it's always worth doing your own comparison before you buy. On a random selection of 30 items across various departments, all but three were cheapest at Costco’s warehouse.

As an example of the discount available, Kikkoman soy sauce (1.9l) cost £6.59 at Costco, but £12.73 for the equivalent amount at the next cheapest supermarket. Lavazza ground coffee (1kg) was £12.99 in Costco – the cheapest elsewhere was £17.20. Though of course, most of these are bulk sizes so you will need space to store, plus you’ll need to pay the £33.60 membership fee.

Can you really eat 2kg of soured cream in two weeks? Okay don’t answer that. But a bargain’s not a bargain if it goes off before you can eat it, so don’t buy lorry-loads of perishables.

Think store cupboard – so prioritise oats, tin foil, cat litter and frozen prawns over, say, pastries, berries and fresh meat.

In what’s probably a loss leader to tempt you in, Costco’s food court sells a hot dog with unlimited soft drink refills for £1.50. You can also grab pizza slices for £1.99 and jacket potatoes for £2.99. If you’ve little ones, this makes for great cheap lunch in the school hols.

Sodas come with unlimited refills (£1.19), so a pro tip is to grab a soft drink before you hit the aisles. That way you can fit in an extra refill after you’ve paid.

Buy something at Costco, and if the price drops within 30 days, you can get a credit note for the difference. (It only matches Costco prices, not other stores’.)

Now normally we’re not huge fans of price promises. In reality, they allow stores to charge what they like, knowing that they just have to reduce the price for the few shoppers who bother to check prices after making a purchase.

However, if you do spot your new 50-inch telly's £300 cheaper a few weeks later, this is worth knowing. You need to fill in price adjustment request form.