Last year, as many as two in three people (69%) who ordered one or more deliveries had a delivery problem over the festive period, Which? has revealed.
The survey of more than 2,000 UK shoppers* found that some people had fragile gifts destroyed after being thrown over fences, while others had to buy gifts twice because orders didn't arrive in time for Christmas day.
Online shopping is expected to surge this year, with lockdown restrictions preventing people from buying in-store.
In a separate survey,** we asked more than 13,000 members about their experience with major couriers between March and August.
We found that some couriers are more reliable than others when it comes to delivery slots, how quickly orders are delivered and where parcels are left.
UPS was consistently the worst courier for keeping customers satisfied across key categories, While Amazon, DPD and Royal Mail customers were the most satisfied.
All delivery firms performed well when it came to maintaining social distancing guidelines.
Here, we look at the courier services you can rely on and explain how to resolve any unwanted delivery disasters.
One in four UPS customers (23%) were unhappy with delivery slots offered and the company's communication with customers, while one in 10 (11%) were not pleased with where the delivery driver left their order.
We heard from a UPS customer who received a smashed computer after the driver delivered it upside down, despite a clear 'this way up' marking on the box.
They tried to arrange a collection over the phone, but were repeatedly cut off by the courier.
'It was only by luck I was in when they arrived to pick it up. Terrible delivery and appalling communication,' they said.
UPS said it delivers an average of 20 million parcels a day and prides itself on reliability and service quality.
It takes damage to goods very seriously and regrets any inconvenience caused. It said it doesn't comment on third-party research.
Looking at how quickly couriers delivered orders, Amazon was the best courier with nine in 10 people (92%) satisfied with the length of time between ordering and delivery.
For communication with customers, Amazon also finished joint top with DPD, with the highest proportion of satisfied customers in this category.
DPD was also the best courier for delivery slots, with more than eight in 10 customers (82%) happy with the slots offered.
Royal Mail had the most satisfied customers in the category for where deliveries were left, with more than nine in 10 (93%) happy with where the driver left their most recent delivery.
It's always frustrating when you wait in for a parcel only for it to not arrive.
Almost a quarter of people (23%) who shopped online last Christmas said at least one delivery did not arrive at all.
One survey participant described how a postcode 'black hole' led to a string of failed deliveries to their home.
'The satnav used to send all the delivery drivers to the wrong address about two miles away,' they told us.
Another said a laptop they ordered didn't arrive but had apparently been signed for the month before.
And one participant waited in all day for their parcel only to find the courier had forged their signature and left it on their doorstep.
Your rights if a parcel goes missing
If your parcel goes missing you can ask the retailer for a refund.
The retailer should deliver your item in the timeframe agreed when you placed your order.
But the absolute maximum time a retailer has to get your delivery to you is 30 days - after which you can request a full refund.
Remember, your rights are with the retailer, not the courier.
If you give permission for your delivery to be left in a specified safe place or received by a nominated neighbour, your rights change slightly.
In this case, if something goes wrong, you'd still be considered to have received the delivery, and might not be able to make a claim with the retailer.
Think carefully before ticking these boxes at the checkout.
Another recurring issue last Christmas was fragile and valuable items being thrown - and subsequently smashed - over fences.
'A box full of presents was thrown over my fence and the rain destroyed all of them,' one respondent told us, while another said their parcel was 'soggy and chewed by a fox', after being left outside in bad weather.
Others were surprised to find parcels left in their bins. 'It was only sheer luck that it wasn't taken by the bin men,' a participant recalled.
Your rights if a parcel is damaged
If your order arrives damaged or faulty, you have a right to refuse it and get a refund, repair or replacement.
You need to take it up with the retailer, not the courier, even if it was the delivery driver who damaged your parcel.
This is because your contract is with the retailer, who you bought the goods from.
Make sure you take photos of the damage and confirm any conversations you have with the retailer in writing if possible.
If the retailer asks you to return the items, you can ask for them to reimburse the postage costs.
Even if the retailer's T&Cs say items are returned at the buyer's expense, this doesn't apply to damaged or faulty goods.
Nobody wants to turn up empty-handed on Christmas day.
But nearly one in five (18%) of us experienced a late delivery the last festive season, and one in 10 (11%) didn't receive gifts in time for Christmas day.
'I ordered a toy robot for my grandson which didn't come until after Christmas and he had gone home,' said one participant. 'I bought extra gifts to compensate.'
Your rights if a delivery is late
If your delivery arrives too late, and it was obvious your order was a gift for Christmas, you can treat the contract as at an end and claim a refund.
Contact the retailer to complain and request your money back.
But if it wasn't clear to the retailer at the point of purchase that your item was a gift needed in time for Christmas, you need to give them another opportunity to deliver your order.
The retailer should also get the parcel to you in the timeframe agreed at the checkout.
If you paid extra for nominated day delivery and the parcel is late, make sure you ask the retailer to reimburse you for the extra money spent on special delivery costs.
Some gift-givers' Christmases took an unexpected plot twist when they received items wildly different from what they'd ordered.
One participant was surprised to receive a carbon monoxide alarm instead of a phone.
Another was baffled to find a bright-red wig in their parcel, having originally ordered a Christmas tablecloth.
Your rights to a refund if you receive the wrong order
If your goods arrive and they're not as described, you're entitled to a refund, repair or replacement.
Make sure you contact the retailer to let them know you've been sent the wrong item.
Take photos of the item you received and ask for a replacement to be delivered as soon as possible.
If it's unlikely the replacement will be with you in time for Christmas, you can ask for a refund.
And if the retailer asks you to send back the incorrect item, you can ask them to reimburse you for delivery costs.
* Populus, on behalf of Which?, surveyed 2,071 UK residents online between Jan 31 and Feb 3 2020.
** We asked Which? members in August about online orders placed between March and August 2020, excluding groceries. The companies were Amazon, DHL, DPD, Hermes/my Hermes, Parcelforce, Yodel, Royal Mail (Signed for), Royal Mail and UPS.