We are aware some Post Offices are advising customers that scissors can no longer be sent through the postal service, the following text extracts are from the Royal Mail website and confirm that scissors, appropriately packed, can be mailed. 

Restricted Goods – Personal Customers
Things we can carry in UK post but with restrictions

Sharp objects Sharp objects like knives, kitchen utensils and gardening tools may only be posted if they are packaged appropriately so that they are no risk to employees, other postal items or recipients.

Wrap heavy cardboard around sharp edges and points, strong enough to ensure that the contents do not pierce the outer packaging. Wrap each item with cushioning material. Place in a suitable outer container such as a padded envelope. The sender’s name and return address must be clearly visible on the outer packaging.

http://www.royalmail.com/search/google_cse_adv/mailing%20scissors

(Scroll down to Dangerous Goods business customer booklet and open, then scroll down to the picture of scissors followed by the text Sharp Objects & Instruments on page 37. These restrictions became effective from the 14th January 2013 )

Sharp objects and instruments (including scissors and kitchen knives or utensils)
UK destinations: Yes
International destinations: Yes

Follow these packaging guidelines: Wrap heavy cardboard around sharp edges and points, strong enough to ensure that the contents do not pierce the outer packaging. Wrap each item with cushioning material. Place in a suitable outer container such as a padded envelope. The sender’s name and return address must be clearly visible on the outer package.