As the first full working day of the year, Tuesday could come as a shock to the system for many returning to the office after the Christmas break.But one business is gearing up for what is likely to be one of its busiest days of the year: Royal Mail. The service has disclosed that staff are being told to expect a 50 per cent jump in the volume of parcels being returned tomorrow on what is being nicknamed “take back Tuesday”.The prediction is based on the number of parcels already logged with Royal Mail through its Tracked Returns service, which is used by more than 1,000 online retailers to enable customers to send back unwanted purchases.The rise of internet shopping has transformed not only the way people buy their Christmas presents but how they dispose of or exchange any unwanted gifts afterwards. Royal Mail expects a 50 per cent jump in the number of parcels to process on Tuesday Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. Instead of the traditional pile of ill-fitting jumpers and unwanted shirts on shop counters in the month of January, customers are increasingly able to return goods by post.Customers using the Tracked Returns service simply select the name of the retailer or supplier from a list of more than 1,000 brands on the Royal Mail website, print off a label and deposit the parcel at a Post Office.The system also enables retailers to track the progress of returned items as they make their way back to warehouses and stores.Parcel volumes are also likely to be boosted by recipients of gifts selling them off on sites such as eBay, which also rely on the mail system. Clothes and shoes are the most likely to be returned Psychologists say the best time to try to sell on gifts is in the window between Christmas Day and New Year when people are thought to be more receptive to exchanging them and on the look-out for bargains.Separate research by Royal Mail found that clothing and footwear are still the most likely items to be returned and that women are driving the returns boom.A survey of online shoppers found that 30 per cent of participants said they had returned women’s clothes, almost twice as many as had sent back men’s or children’s clothing. Last year the first full day back after Christmas was nicknamed “mail-back Monday” as Christmas and New Year’s Day fell on Fridays rather than Sundays. Unwanted Christmas presents will be sent back on Tuesday Recent research published by eBay claimed that British people open an estimated 115 million less-than-desirable gifts, worth as much as £2.2 billion, every year.The study, based on a poll of 2,000 adults, found that almost a third of people reported having “little or no attachment” to some gifts only a few days after Christmas.Last year eBay had more than 4,500 items listed specifically as “unwanted Christmas gifts” in the first two weeks of January alone.But those determined to make a killing from unwanted Christmas presents could already have missed the boat.