Background The Labour Force Survey (LFS) is a unique source of information using international definitions of employment and unemployment and economic inactivity, together with a wide range of related topics such as occupation, training, hours of work and personal characteristics of household members aged 16 years and over. It is used to inform social, economic and employment policy. The LFS was first conducted biennially from 1973-1983. Between 1984 and 1991 the survey was carried out annually and consisted of a quarterly survey conducted throughout the year and a 'boost' survey in the spring quarter (data were then collected seasonally). From 1992 quarterly data were made available, with a quarterly sample size approximately equivalent to that of the previous annual data. The survey then became known as the Quarterly Labour Force Survey (QLFS). From December 1994, data gathering for Northern Ireland moved to a full quarterly cycle to match the rest of the country, so the QLFS then covered the whole of the UK (though some additional annual Northern Ireland LFS datasets are also held at the UK Data Archive). Further information on the background to the QLFS may be found in the documentation. Secure Access QLFS data Secure Access datasets for the QLFS are available from the April-June 1992 quarter, and include additional, detailed variables not included in the standard 'End User Licence' (EUL) versions (see under GN 33246). Extra variables that typically can be found in the Secure Access versions but not in the EUL relate to:geography (see 'Spatial Units' below)date of birth, including dayeducation and training: including type of 'other qualifications', more detail regarding the number of O'levels/GCSE passes, type of qualification gained in last 12 months, class of first degree, type of degree held, UK country of highest degree, type of current educational institution, level of Welsh baccalaureate, activities to improve knowledge or skills in last 12 months, attendance at adult learning taught courses, attendance at leisure or educational classes, self-teaching, payment of job-related training feeshousehold and family characteristics: including number of family units (and extended family units) with dependent children only, and with non-dependent children only, total number of family units with more than one person, total number of eligible people, type of household, type of family unit, number of bedroomsemployment: including industry code of main job, whether working full-time or part-time, reason job is temporary, payment of own National Insurance and tax, when started working at previous job, whether paid or self-employed in previous job, contracts with employment agencyunemployment and job hunting: including main reason for not being employed prior to current job, reasons for leaving job (provision of care or other personal/family reasons), use of internet for job hunting, if and when will work in the futuretemporary leave from work: including proportion of salary received and duration of leaveaccidents at work and work-related health problemsnationality, national identity and country of birth: including whether lived continuously in UK, month of most recent arrival to UK, frequency of Welsh speakingoccurrence of learning difficulty or disabilitybenefits, including additional variables on type of benefits claimed and tax credit paymentsSecure Access versions of QLFS household datasets are available from 2009 under SN 7674. Prospective users of a Secure Access version of the QLFS will need to fulfil additional requirements, commencing with the completion of an extra application form to demonstrate to the data owners exactly why they need access to the extra, more detailed variables, in order to obtain permission to use that version. Secure Access users must also complete face-to-face training and agree to Secure Access' User Agreement (see 'Access' section below). Therefore, users are encouraged to download and inspect the EUL version of the data prior to ordering the Secure Access version. Well-Being variables are not included in the LFS Users should note that subjective well-being variables (Satis, Worth, Happy, Anxious and Sad) are not available on the LFS, despite being referenced in the questionnaire. Users who wish to analyse well-being variables should apply for the Annual Population Survey instead (see SNs 6721 and 7961). LFS Documentation The documentation available from the Archive to accompany LFS datasets largely consists of the relevant versions of each volume of the user guide. However, LFS volumes are updated periodically by ONS, so users are advised to check the ONS LFS User Guidance pages before commencing analysis.