None of us expect the supermarket to have every item available at all times. When we're trawling the shelves, there are times when we've all settled for a different brand of chopped tomatoes or a slightly larger box of cereal. When we're making our own substitutions, finding the most suitable alternative is never much of a challenge. However, when we shop online, those picking items for our delivery don't always seem to have quite so much luck.
And while we've tutted and rolled our eyes when we're received jam instead of marmalade or crumpets instead of bread rolls, there are some times when substitutions have gone far more spectacularly wrong.
We reveal our ten favourites:
1. Whisky instead of baby wipes
We reported at the end of last year on the man who ordered a £6.64 packet of baby wipes from Asda, and received a £18.50 litre bottle of whisky instead. The delivery note went viral - with plenty of people suggesting they were both useful tools to help busy parents cope - and Asda quickly delivered the wipes.
2. Octopus instead of walnut bread
In 2014, a creative Tesco employee was unable to lay his hands on the walnut bread that had been ordered - so he provided a whole octopus instead. The customer shared it on Twitter, at which point Tesco offered to refund him 'a couple of squid'.
Asda impressed another shopper, who had ordered Ricola sugar free sweets, and received five tins of pilchards instead.
4. Blackberries instead of potatoes
Sainsbury's isn't flawless in the substitutions department either - in one instance substituting baby new potatoes with blackberries.
5. Aubergine instead of limes
Tesco clearly decided that the best substitute for a lime wouldn't be a bag of limes, or a lemon - but an aubergine.
6. Pomegranate instead of hair conditioner
One Mumsnet user reported having ordered pomegranate scented conditioner from Asda, and when the picker couldn't find it, they substituted it with a real pomegranate.
7. Marshmallows instead of baking trays
The Mirror recently asked its readers about their favourite substitutions, and one woman revealed she had ordered foil baking trays from Tesco - and received a bag of marshmallows instead.
8. Floor cleaner instead of lemons
A study by Which? a few years ago revealed that one Sainsbury's shopper had ordered fresh lemons - and got Flash lemon scented floor cleaner instead.
9. Chocolate pudding instead of black pudding
The Which study revealed that one picker decided that all puddings were basically the same, and in the absence of black pudding, packed chocolate pudding instead.
10. Weird wine substitutions
The Guardian reported on a man who ordered a bottle of red wine and a bottle of white for a dinner party. He received a bag of crisps and three tins of sweetcorn instead.
It seems that in these instances, a not-particularly-intelligent computer system makes suggestions based on matching words - like pomegranate or pudding. The idea is that this should be interpreted by the picker, who will decide whether it's a sensible suggestion. The problem seems to be that instead of thinking it through, some are just blindly picking whatever the computer suggests.
If you frequently run into this kind of problem, the good news is that you can turn substitutions off on your orders, so if an item isn't available, you just go without. You will also get a chance to go through all your substituted items, and decide whether or not to accept them, before your delivery driver leaves.
But what do you think? What's the weirdest substitution you have ever received? Let us know in the comments.