I just recieved an email with a code for 20% off a spend over £100. I have tried it and it does apply to sale and discounted products. It must be over £100, if its exactly £100 doesnt work.
Terms and conditions: 20% off is valid on purchases of £100 or more online at mothercare.com (using discount code CMDF). This voucher code is valid for a limited time only and mothercare have the right to amend or withdraw the promotion at any time. This voucher/voucher code cannot be used in conjunction with any other voucher/discount code, or in conjunction with any free car seat offers, or with Mothercare and ELC staff cards or with childcare/nursery discounts, in concessions or to purchase baby milk, baby medicines, nappies, Bugaboo, Philips AVENT Natural, TP or Plum products and gift vouchers/cards. This voucher is not transferable and should not be distributed to the wider public. Voucher codes should not be sold on auction sites for profit or reproduced on any website. P&P charges are not subject to 20% off discount.