Security Clearance & Vetting


UK Government


International Recognition

UK Civilian




This page contains information regarding the Clearance and vetting of staff, all information has been derived from Open Source and the extracts are uncontrolled, the information is provided for reference by Computer Network Defence Ltd staff and details/enquires should always be verified with your Vetting Agency.  If you have UNCLASSIFIED information which may enhance this page please pass it over.

UK Government

Most of the information below was taken from the DVA website.  However, there are a number of other Agencies also carrying out thier own Security Clearances and there appears to be a league table, where one Agency won't accept the Security Clearance granted by another Agency without further checks, this results in delays, even if the candidate appears to have the necessary DV etc


The UK Defence DVA states that you do not require Security Clearance in order to bid for MOD work as it may give cleared individuals a competitive advantage. The practise of requesting Clearance by agencies is discouraged.  However, it has been Computer Network Defence's experience that the urgency of many requirements makes the presence of existing clearance inevitable.


The same therefore applies to the inclusion of the level of Clearance on your CV, whilst it is not recommended by the Authority, there are so many candidates doing it, that to not do so would preclude you from too much work.  In our opinion, there are 2 categories to this, those looking for permanent work and those looking for contract roles.  We often see permanent staff taken on for SC roles without clearance, though not nearly as many for DV roles, this is probably due to the additional time taken and the risk of them not getting clearance.  For contractors there are very few roles which will clear you to SC and even fewer to DV, therefore in order to compete most contractors include their clearance level on their CV, though some just type DV, without any context to what it means, this will be picked up by Agency keyword searches. 


The most frequently asked question we get is "I've just left a security cleared job, what happens to my clearance" .  The DVA advise that the clearance can be resurrected for 12 months after leaving a security cleared post, after which time it lapses and requires a full re-vetting.  Our advice is to transfer it to a Security Controller on a List X site, then you know exactly where it is, they may also tell you when it is due to expire (as apposed to lapse).  It will still lapse after 12 months, if you don't use it, transferring it between security controllers is easy when you do get a role.  Please get in touch if you require advice or assistance. 


Wikipedia describes a List X site as "...A List X site is a commercial site (i.e. non-Government) on UK soil that is approved to hold UK government protectively marked information marked as 'confidential' and above. It is applied to a site and not a company...."  List X status cannot be publicly advertised, therefore we cannot recommend any companies which may assist you on this website.


To gain Security Clearance you need a sponsor. Individuals and companies cannot ask for a security clearance unless they are sponsored, and you will not be sponsored unless they are contracted to work on one or more specific classified projects.  A recent petition was launched on the 10 Downing Street website to challenge this ruling, though as yet it still stands.


Security Clearance Expiry

The length of time Security Clearance remains valid varies according to the risk, to our knowledge, Crown Servants DV clearance lasts for around 8 years, whereas,

Security Clearance within the UK Government and Defence consists of 3 main levels, these are defined as follows:


Counter Terrorist Check (CTC)  

for people employed in posts with proximity to public figures, access to information or material assessed to be of value to terrorists or unescorted access to establishments assessed to be at risk from terrorist attack. A CTC does not allow a person access to, or knowledge of, protectively marked assets.

Security Check (SC)

for people employed in posts which have substantial access to SECRET assets or occasional controlled access to TOP SECRET assets.

Developed Vetting (DV)

is needed for people with substantial unsupervised access to TOP SECRET assets.  The DV process is extensive and some may say intrusive, it includes a check of your identity and employment and education references.  You will be required to complete security and financial questionnaires. Criminal records and credit reference will be checked, and a check against Security Service records.  Some of your references will be double checked by writing to or interviewing the people concerned. You will also be interviewed by a Vetting Officer.  The Vetting Medical Adviser may contact your doctor to identify certain medical and psychological conditions that could affect whether the Authorities think you are suitable to handle sensitive information.  If you refuse access to your medical reports, your vetting clearance may be refused.  You may also be requested to provide your partner's financial records.


Some organisations have higher benchmarks for Protective Marking/Clearance mapping and mandate DV as a prerequisite for certain compartments below TOP SECRET


How Long Will Security Clearance Take (DVA)

Clearance Level Routine Priority Immediate
CTC 30 days 10 days  
SC 30 days 10 days  
DV 95 days 30 days  

The above timescales do not include other agency checks, we have also been advised that priority clearance is rarely granted for project work

Security Clearances lapse 12 months after leaving a post where it is required, if you rejoin a security cleared post within 12 months, there is usually no need to be vetted again.  It should be noted that when you initially receive security clearances the Vetting Officer will state how many years the Clearance is valid before rechecking, in certain cases extensions can be authorised.


It should also be noted that transferring clearances between agencies can result in full or partial rechecks, regadless of how recent the last check was performed.


Baseline Personnel Security Standard (BPSS)

Formerly Basic Check (BC) and Enhanced Baseline Standard (EBS) (formerly Enhanced Basic Check (EBC)): These are not formal security clearances. They are a package of pre-employment checks that represent good recruitment and employment practice. A BPSS or EBS aims to provide an appropriate level of assurance as to the trustworthiness, integrity, and probable reliability of prospective employees whose work involves access to CONFIDENTIAL assets or information. The check is carried out by screening identity documents and references.


UK Codeword Working

For obvious reasons these are beyond the scope of this page, please don't call to ask for more information we will not provide it.  However, they only last whilst you are in Post, you will be Read On prior to start and Read Off at the end, therefore once you move on they don't count, we occasionally find ex-military candidates using them as though they are certifications.  Please don't include any codewords on your CV!


International Recognition

Some countries will recognise another 'friendly' country's Security Clearance, we will try and find who trusts who from an Open Source.  In our experience if you wish to work in or visit a Friendly nation and the visit is a joint venture between the 2 nations, then the transfer or recognition of the Security Clearance happens.  However, if you wish to work for another country without it being a collaborative effort between the nations then it gets decidedly more difficult



NATO has four levels of security classification; NATO RESTRICTED (NR), NATO CONFIDENTIAL (NC), NATO SECRET (NS) and COSMIC TOP SECRET (CTS). NATO's clearance levels function independent of any clearance levels for other nations. However, it is understood that for most NATO nations, granting of a NATO security clearance is handled in a similar manner to that of obtaining a national security clearance.


UK Civilian


BS 7858

BS 7858 is a key security standard that tells you how to screen staff before you employ them. BS 7858 gives recommendations for the security screening of individuals to be employed in an environment where the security and safety of people, goods or property is of extreme importance. It also applies when there is a requirement of the employing organization’s operations and/or where such security screening is in the public interest. This revision takes account of the Private Security Industry Act 2001. The Act requires that any person engaged in licensable activities, as designated in the Act, be licensed in accordance with the Act. It is an offence to engage in licensable conduct when not in possession of the appropriate licence. This edition introduces criminality checks if the activity undertaken is not licensable, requires organizations to combat identity theft and fraud, introduces credit reference checking, and addresses the increasing frequency with which employees change jobs.



BPSS stands for Baseline Personnel Security Standard and is the minimum standard recommended by the government when recruiting personnel who will not require access to Secret or Top Secret government information. BPSS background checks offer a minimum level of vetting which contractors and service providers may find easier and quicker to complete; this allows contractors an improved opportunity to tender. However, given the lower level of checks carried out BPSS is not therefore suitable if you have a requirement for personnel to work on an immediate, short-term contract as the security checks required might not be completed within your timescales.


Criminal Records Bureau (CRB) 

Is required for posts that involve working with children or vulnerable adults. Standard Disclosures may also be issued for people entering certain professions, such as members of the legal and accountancy professions. Standard Disclosures contain the following; details of all convictions, cautions, reprimands and warnings held on the Police National Computer (PNC);


Enhanced CRB checks

are required for posts involving a far greater degree of contact with children or vulnerable adults involving regular caring for, supervising, training or being in sole charge of such people i.e. Teacher, Scout or Guide leader. Enhanced Disclosures contain the same information as the Standard Disclosures but with the addition of local police force information considered relevant by Chief Police Officer(s).


Credit Reference Check

Many companies run credit reference checks, to check your's go to