Delivery company Yodel says the backlog of parcels following the spending splurge on Black Friday and Cyber Monday will be cleared by tomorrow as its competitors handled their busiest night of the year.
Yodel has left a message on its main number warning that customers could still be experiencing a "slight delay" after it was forced to temporarily suspend new collections from retailers last week.
Executive chairman Dick Stead said: "The build-up of parcels at our national sort centres last week was cleared at the weekend.
"Many of these deliveries have already been made and will be completed by tomorrow. We would like to apologise to anyone whose parcel was affected by this.
"We are now operating a normal Christmas service. New parcels are coming into our operation and flowing freely through our network.
"A small number may be subject to a slight delay, as is normal for this time of year, and we're working to ensure all deliveries are made as swiftly as possible."
Waterstones, which uses Yodel, said the courier company's difficulties at the end of last week affected about 50% of its next day deliveries, delaying these generally by 24 hours.
However it said the majority of customers choose free shipping options which promise 72-hour delivery, and just 1% to 2% of these were not delivered on time.
Waterstones said: "In short, only a small number of customers of Waterstones have been disappointed by Yodel. That said, we have seen a very marked and substantial shift to click-and-collect by our customers with volumes up greatly.
"These, of course, are unaffected by Yodel's difficulties."
DPD said it coped with its busiest night of the year last night as items bought over the weekend made their way to its hub for sorting.
Chief executive Dwain McDonald said: "Our daily parcel volumes are up 21% to 24% consistently above last year, but that is what we planned for.
"There was a significant spike in volumes on Cyber Monday but we delivered everything to target and our performance so far has been ahead of expectation."
TNT said it had almost 500 temporary workers in place to deal with extra demand and expected to increase its fleet capacity between 15% and 20% in the lead-up to Christmas.