Monday was a big day for online retailers on both sides of the Atlantic – and while sales in the UK may not have been as high as hoped, its web sites were at least up to the challenge of record volumes.

Meanwhile, in the States, Cyber Monday as it is dubbed, saw record breaking traffic and a whole host of retailers experience problems on their sites.

Household names such as Gap, Borders, Sephora, Home Depot, Victoria’s Secret, Costco, Staples and Dell are all reported to have been affected.

Simple web site coding and search engine problems are thought to have been two of the reasons for site downtime, reasons that probably won’t cut it with retail chief executives on what should have been one of the biggest shopping days of the year.

So the spike in visitor numbers didn’t translate into a sales surge — perhaps not surprising given the number of sites having problems and the huge discounts on offer when they were up and running properly.

Back on this side of the pond, Monday was also a slight disappointment in terms of sales revenues, according to IMRG, but transaction volumes were the highest ever recorded.

UK retailers seem better prepared for growth in visitor numbers and transactions, and could teach their US peers a thing or two about planning for the online peak.

However, with customer behaviour online changing, only a few UK retailers have really been tested so far this season.

IMRG says that it expects peaks on UK web sites to be much more patchy, and based on promotional activity rather than the traditional patterns that retailers have come to expect with Monday’s in December being the biggest online shopping days.

The biggest test of whether retailers can cope with this so far has been during the discount days run by Marks & Spencer and Debenhams at the end of November.

While M&S excelled, Debenhams’ home page crashed, causing it to leak a substantial amount of traffic to its main competitors.

The money being spent online in the UK probably won’t shoot up this year by the same growth rates that have seen in the past. But there is still a substantial opportunity for individual retailers to maximise their online growth by making sure that customers can easily find and use their site.

Going on their poor performance on Monday, US retailers still don’t get this. Whenever the individual peaks come for UK retailers this year, those who ignore the basics do so at their peril.