Last month, Microsoft launched an offer on its Surface Book and Pro 4 in the UK, giving away a free Surface Dock and Pen Tip Kit - worth a total of £174.99 - with either device.
That deal was originally due to end on June 1 - but the company has now extended the offer until June 6.
The Surface Dock features two Mini DisplayPorts, four USB 3.0 ports, one audio-out and one Gigabit Ethernet port. The Surface Book is priced from £1,299 in the UK, while the Surface Pro 4 starts at £749.
Buyers with more modest budgets can take advantage of another deal, offering £70 off the entry-level Surface 3, bringing its price down to £349. The company is also offering £50 off the next model up in the range, along with 40% off the Surface 3 Docking Station.