Workers Registration Scheme (WRS) Query

I'm an EEA national from an A8 country, Czech Republic.

I've lived and worked in the UK full time for the last 9 years.

My naturalisation application was rejected because I did not register for the WRS for 12 months.

When can I re-apply for naturalisation and not be rejected for this reason?

Note that the WRS scheme was abolished in 2011.

As you were not registered with the WRS, you can only acquire PR in May 2016 at the earliest. The requirement for citizenship is to be settled (in the case of an EEA national to hold PR status) and to have held this status for 12 months prior to applying for naturalisation. As the Worker Registration Scheme was abolished on 30 April 2011 the earliest you can make an application for BC which stands success should hence be in May 2017 (unless you are married to a British citizen, in this case it would be May 2016). This is provided that you fulfil all other requirements for naturalisation as a BC; note that the requirement to hold a Document Certifying PR has been added to the list on 12/11/2015.

Did you register for WRS at all or not at all?
If not at all, previous advice holds good.

If you registered late & got a certificate (late)
then you may be able to apply 5 years after that (unless you changed jobs inside 12 months & failed to re-register within 30 days).