(This Oct. 29 story in paragraph 3, corrects name of Frères Branchiaux Candle Press to Frères Branchiaux Candle Co)

Arriana McLymore, Lisa Baertlein

NEW YORK, NY (Reuters] – Online shoppers looking to purchase holiday gifts this year will need to plan ahead. Numerous retailers are setting earlier deadlines for merchandise ordered online to reach customers’ homes before Christmas.

Frères Branchiaux Candle Co co-founder Celena Gill designated Nov. 30 as the last day for customers to place their orders if they want scented soy candles to arrive before Christmas. “We have already seen a delay in shipping this month and we anticipate that it will be worse as we near Christmas day,” Gill said. She refused to discuss last year’s shipping deadline.

State Bags, a New York-based luggage company, is cutting off Christmas shipping three days earlier than last year’s deadline of Dec. 18. Jacqueline Tatelman co-founder said the company will not be offering its two-day holiday shipping promo this year because of supply chain issues.

FedEx (NYSE:) and United States Postal Service set ground shipping deadlines for Dec. 15, identical with last year’s delivery cutoffs – even though there is one day more between Thanksgiving and Christmas this year. UPS offers delivery timeline estimates through its website. These are based on shipping service, timing and location.

Some estimates suggest that delivery drivers may have to handle nearly five million additional packages daily during peak season, when volume can almost double. FedEx is already having problems with its ground division, which delivered more than 9.3million packages per hour for Walmart customers (NYSE:) in the last quarter. The Memphis-based firm warned in September that problems with employee retention and hiring were slowing delivery.

UPS, the world’s biggest parcel delivery firm, is dropping low-profit customers – a move that could hit vulnerable retailers. On the other hand, UPS will make nationwide deliveries on Saturdays this year and is taking several other steps to minimize “chaos costs” and improve on-time service, UPS Chief Executive Carol Tome said.

To appeal to last-minute customers, retail stores often use delivery cutoffs as competitive differentiation. However, this strategy comes with additional risk in 2018, especially for small shops which are more vulnerable to negative customer reviews. And, in a year marked by hurricanes and other severe storms, there’s little wiggle room for other unforeseen disruptions due to factors such as wicked winter weather.

This year retailers, large and small alike, are encouraging their customers to shop early in order to shift the demand and improve supply chain backups. Tome, a U.S. analyst said that some shoppers fear supply chain problems will lead to Christmas gift delivery at home.

“In fact, some think that 50% of holiday shopping will be completed by Cyber Monday,” said Tome. “Some of our customers are actually pulling forward promotions,” she said, referring to retailers’ earlier Christmas marketing messages that translated into a bump in demand.

UPS started working with Amazon.com, its largest customer, several months before. Still, it will again enforce volume limits and not pick up all requested packages if unexpected volume threatens to swamp its system – a move that hit retailers like Gap, Macy’s and Nike (NYSE:) Last year.

Shopify (NYSE) has encouraged merchants updating their shipping policy pages. This will highlight any delays or lower expectations. It is also recommending that merchants start offering Black Friday-Cyber Tuesday sales, and include local delivery options and curbside pick-up for brick-and mortar merchants.

Etsy (NASDAQ): has been improving the accuracy of its delivery estimates to boost sales and lower uncertainty for vintage sellers. “Nearly every item from a U.S. seller will include an estimated delivery date this holiday season,” Etsy CEO Josh Silverman said in a blog post.

Walmart and other large retailers are also available. Target (NYSE:), Amazon, Macy’s and Best Buy have not announced their final delivery cutoff dates, but they are promoting options to reduce stress on the system. They’re offering early and extended Black Friday deals and enticing customers to use gig delivery services like DoorDash and Shipt or “buy online, pick up store” options.

Walmart and Amazon announced their delivery dates in December last year. Amazon, however, notified its customers at the beginning of November that they were offering two-day or one-day shipping for eligible products on Christmas Eve and Dec. 23.