Guidance for Returning Officers administering a Senedd election

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Ballot paper colour

The colour of the ballot papers is not prescribed by law.

Tendered ballot papers must be a different colour from the ordinary ballot papers.1

The EMB may recommend or direct the colours to be used. 

In deciding on the ballot paper colours, you should take into account accessibility issues relating to colour and contrast. 

The official mark

The official mark is a security mark that must be added to ballot papers.2

The official mark:

  • can be the same for all ballot papers at an election or different official marks can be used for different purposes at the same election, for example one for postal votes and another for polling station ballot papers
  • cannot be re-used for seven years at elections for the same Senedd constituency The mark should be distinctive. 

It could be a printed emblem or mark or a special printing device such as a watermark. It could also be a perforation added at the time of issue of the ballot paper, if stamping instruments are used to create a perforating official mark.

The mark should be capable of being seen on the front of the ballot paper so that it can be seen without having to turn the ballot paper over.

The EMB may recommend that the official mark used on ballot papers to be issued in polling stations should be different to the official mark used on ballot papers to be issued in postal vote packs.

Ballot paper numbers

Ballot paper numbers should run consecutively, but do not have to start at 1. Ballot paper numbers should be unique, and should not be reused, for example the polling station, postal vote, and tendered ballot papers should all be numbered differently.

Unique identifying mark

The unique identifying mark (UIM) can be made up of letters and numbers and could be a repeat of the ballot paper number with the addition of a prefix or a suffix. The UIM can instead be, but does not have to be, a barcode. It is important to remember that the UIM is not the same as the official mark. 

The UIM:

  • should be unique for each ballot paper
  • can be re-used at the next poll
  • must be printed on the back of the ballot paper3

Form of the reverse of the ballot paper

The form of the reverse of the ballot paper is prescribed and you must ensure that the required information is included on the ballot paper reverse in the specified format.4 There is no provision to put any hatching or other marks on the back of the ballot papers.

Last updated: 27 April 2026