Companies waste £££ every year by not getting their discounts from Royal Mail for postage. Discounts are available of up to 35% for bulk mailing off the standard Royal Mail tariff and volumes start from as little as 1000 items. The discounts vary according to weight, size and percentage that is post-coded (90% min). All the mailing houses will give the full discounts
Business Mail Pricing from April 7th 2008 PDF
Bulk Mail Pricing from April 7th 2008 PDF
Royal Mail also have a rather nifty calculator that lets you calculate the cost of your bulk mailing. Click here for the link