Smith's will abandon the expensive premises behind Sloane Square where several hundred staff are employed. A handful will be transferred to a cheaper London location though this has not yet been named.
Most of the job cuts will be at the Swindon offices where the core WH Smith retail chain is based. A shake-up of senior management is also expected.
The changes are the fruits of a three-month review of the business undertaken by new chief executive Bill Cockburn, who joined the company from the Post Office.
He is also expected to make an announcement on Do It All, the loss-making DIY chain it jointly owns with Boots. Mr Cockburn is likely to signal his desire to sell the chain as its closure would be too expensive.
WH Smith will need the agreement of Boots, which announces its results this week. Boots is under less pressure to bite the bullet on Do It All as it has net cash of almost pounds 600m.
Candidates to buy all, or more likely, parts of the 192-strong chain include market leader B&Q and Wickes. Sainsbury's Homebase may be interested, though it is still integrating the Texas Homecare stores it acquired from Ladbroke last year. There could be interest from foreign buyers.
Mr Cockburn, who joined WH Smith from the Post Office, is expected to announce plans to focus more on the main WH Smith brand, which has been suffering from falling footfall on the high street and increased competition from supermarkets.
Mr Cockburn is thought to be keen to increase sales and margins at the stores. Almost 40 per cent of WH Smith customers leave without buying anything. The average spend is only pounds 5.Reuse content