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Background Notes and Methodology

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The results presented in this publication are based primarily on data-linking of pseudonymised data sources held by the Central Statistics Office. The primary data source used is data on tenants, tenancies, properties and landlords of the Housing Assistance Payment (HAP) scheme.

The following data sources are also used and linked with the HAP datasets

  • Residential Tenancies Board Register
  • Person Income Register
  • P35L Employee level data
  • PAYE Real Time Data
  • Central Record System
  • Department of Employment Affairs and Social Protection's Long and Short-Term Social Welfare Payments Data
  • Integrated Short Term Payment Systems Data
  • Local Property Tax
  • Summary of Social Housing Assessments Data
  • Directory of Irish Property Addresses (Geo Directory)

The linkage and analysis was undertaken by the CSO for statistical purposes in line with the Statistics Act, 1993 and the CSO Data Protocol

Before using personal administrative data for statistical purposes, the CSO removes all identifying personal information including the PPSN and Eircode. The Personal Public Service Number (PPSN) is a unique number that enables individuals to access social welfare benefits, personal taxation and other public services in Ireland. The CSO removes the PPSN and creates a pseudonymised Protected Identifier Key (PIK). The PIK is a unique and non-identifiable number which is internal to the CSO. A similar process is undertaken to create an Eircode PIK. Using the PIK enables the CSO to link and analyse data for statistical purposes, while protecting the security and confidentiality of the individual data. All records in the matched datasets are pseudonymised and the results are in the form of statistical aggregates which do not identify any individuals.

Data Sources

Housing Assistance Payment (HAP) data

The data relates to details of all tenancies, tenants, properties and landlords that have been involved in the HAP scheme since its introduction in 2014. More information on the HAP scheme can be found at  The dataset used in this publication contains a cut of live tables as of 4th June 2020, containing all relevant records since the inception of the scheme until this date. However, only HAP tenancies started up to and including 31st December 2019 are used in this analysis. All analysis within this publication which relates to the local authority of the HAP property, tenancy, household or tenant is from the location of the property as provided in the HAP dataset. The exception to this is for a small amount of historical tenancies previously identified as being in Cork County which have been re-assigned to Cork City based on 2019 boundary changes. Lower level geographies used in the publication are created from geocoding done within the CSO.

Analysis related to start year in HAP relates to the first year which the person/household can be identified in a active HAP tenancy regardless of whether they have subsequently left and re-entered the scheme. Analysis relating to exit year - unless stated - final exit from HAP having not returned prior to the end of 2019.

Person Income Register (PIR) 

The PIR is a pseudonymised income register held internally within the CSO. It contains information on income received by individuals relating to employment, self-employment and social transfers. It is derived from administrative holdings held by the Revenue Commissioners and Department of Employment Affairs and Social Protection. Therefore, the PIR provides a near complete picture on individual level income, for a calendar year.  All linkage is carried out by using a PIK assigned on each contributing data source. The PIK is then used to link the pseudonymised data sources together in order to create the PIR. The PIK protects a person’s identity but also enables linking across data sources and over time. The PIK enables high quality deterministic matching thus significantly reducing/eliminating linkage error.

P35L Employee Level Data

This dataset contains P35L (annual employee- level return by employers) data, as received from Revenue Commissioners combined with CRS (Client Record System) for Gender and Month of Birth and with CBR (Central Business Register) for CBR, NACE (Statistical classification of economic activities in the European Community), and Legal form. This dataset is only used within this analysis to obtain NACE sector for employees up until 2018 (otherwise P35 income is obtain from the PIR). 

PAYE Real-Time Data

This dataset details real-time employee level payroll returns as received from the Revenue Commissioners since a new system of payroll report came into place from 2019. This has been combined with CRS (Client Record System) for Gender and Month of Birth and with CBR (Central Business Register) for CBR, NACE (Statistical classification of economic activities in the European Community), and Legal form. This dataset is used within this analysis to obtain NACE sector for employees and P35 income for 2019.

Residential Tenancies Board (RTB) Register

The Residential Tenancies Board (RTB) register contains information on all tenancies registered by landlords, both private and Approved Housing Bodies (AHB). This contains details of associated tenants, properties and landlords. It is known that the RTB data does not include details of all tenants as landlords may not provide details of all tenants within a tenancy. It is also expected that there is an unknown number of rental tenancies not registered with the RTB.

Central Records System (CRS)

The Central Records System (CRS) is a system within the Department of Employment Affairs and Social Protection (DEASP) which holds data on Customers, including identify data, Addresses, Relationships, Claims, PPS Contributions, Earnings, Employments and Employers. As such it is a central repository of basic personal data on individuals held on different systems within DEASP

Department of Employment Affairs and Social Protection's Long and Short-Term Social Welfare Payments Data

This dataset details extracts of payments from DEASP's Business Object Model System (BOMI) covering all long and short-term schemes. Each payment recorded in the the Integrated Short-Term Payments System (ISTS) is recorded here. The CSO has data from 2013, however data from 2015 only is used for this analysis (the ISTS dataset - see below - is used in some cases for earlier years).

Integrated Short Term Payment Systems Data (ISTS)

The Integrated Short-Term Payments System (ISTS) is weekly containing all claims and payment that week. Additionally, this details those claims closed during that week. Since 2015 this data is fully incorporated into the DEASP payment file detailed above so this is only used in this analysis for earlier years and only for the purpose of tracking Rent Supplement.

Local Property Tax (LPT)

This dataset details local property tax (LPT) returns from all liable residential properties on an annual basis. This includes details of the liable persons and properties. Two instances of this file - 2016 and 2019 - have been geocoded within the CSO to provide an estimated Eircode (and other geographies) for each property. The CSO has added a identifier to the dataset indicating properties which are owned by local authorities and are as such local authority owned social houses.

Summary of Social Housing Assessments Data (SSHA)

This data includes the SSHA (Summary of Social Housing Assessments – annual report) data that the Housing Agency received from LGMA in 2016, 2017, 2018, and 2019. The dataset contains two datasets containing details of gross persons and net households detailing persons and households on the social housing waiting lists (net and gross lists) for local authorities within Ireland. The data received by the CSO does not include persons or households for Cork City, Wicklow, Galway County and Longford. Additional persons and households on the gross lists have not be provided for the four Dublin Local Authorities.

Net lists include households qualified for social housing support across the country at a certain count date but excludes those who have been provided with some social housing support (such as local authority rented accommodation, Voluntary/Co-operative housing, RAS or HAP) and are waiting for a transfer. Therefore, the data in this dataset is of those households that are considered to be the ‘Net Need’ of social housing support.

Gross lists include persons from all applications provided by the local authorities. This data therefore includes persons whose current tenure type is LA rented accommodation, Voluntary/Co-operative housing, RAS or HAP and have applied for a transfer. 

The 2019 count date was 24 June. For the previous years, the count dates were 11 June 2018, 28 June 2017, 21 September 2016.

For analysis within this publication looking at basis of need and classification of need from the housing list data this examines the first available basis and classification of need from the net and gross lists from 2016 to 2019 (i.e. capturing their reasons and requirements for being on the housing list). Analysis on tenure type identifies this from the most recent net list prior to first entering HAP. Gross lists cannot be used for tenure type because HAP would be recorded as the tenure type for HAP tenants on these lists.


Income used in this analysis is Earned Income which is annual gross earnings for the relevant year from P35 employee income (including income as a director) and IT form 11 self-employed trading income before deductions such as tax and PRSI from Revenue. Unless stated, this is at a household level combining the above income from both the main and joint tenant from HAP - provided these persons are 18 or over. Income is only considered in analysis where one or more of the persons within the household has €500 or more annual gross earned income and 2 or more weeks of PAYE or self-employed employment in the relevant year. Individual earned income is capped at €200,000 per annum.

Persons with less than €500 annual gross pay from P35 employee income are not considered to be in PAYE employment nor are those with less than 2 weeks of PAYE employment

Persons with less than €500 IT form 11 self-employed trading income are not considered to be self-employed nor are those with less than 2 weeks of self-employed trading

Where stated, income from years prior to 2019 is inflation adjusted based on changes in the CPI (2011 base) between the December CPI of the relevant year and the December CPI of 2019.

For analysis relating to income of persons/households before/in/after HAP, data from all relevant HAP tenants are considered from 2014 to 2019 with earned income looked at from 2012 (two years prior to 2014) to 2018 (latest year of full earned income available). In some instances, 2019 earned income has been calculated using a combination of 2019 PAYE income and inflation-adjusted 2018 self-employed income.

For the NACE sector categorisation each person is attributed to the NACE sector of the PAYE employment for which they have the highest gross pay in the year. Only those with €500 or more of PAYE gross pay and two or more weeks of employment are included.

Other Definitions

Rent Pressure Zones

Rent Pressure Zones (RPZs) referred to in this publication are designated areas where rents cannot be increased by more than 4% per annum, unless certain exemptions are applied.


All geographical analysis is based on latest available boundaries. This includes analysis related to time periods prior to boundary changes. For example, all local authority level analysis in Cork is based on property location in relation to the new boundaries after changes in May 2019.

Reasons for HAP Exit

HAP tenancy exit reasons used in the publication are from cessation reasons given in the HAP dataset.

Unless otherwise stated, all analysis of exits within this publication solely concern a households most recent exit from a HAP tenancy and only includes those households that have yet to return to HAP prior to the end of 2019.

These reasons are typically provided by the tenant and/or landlord. In this publication the reasons have been categorised into the following groups:

Tenant Non-Compliance including 'Anti Social Behaviour', 'Non Payment of HAP Weekly Differential Rent', 'Non Payment of Top Up Landlord Monthly';

Landlord Ends Tenancy including 'Landlord In Receivership', 'Landlord Selling the Property', 'Landlord gave notice to Tenant';

Accommodation/Landlord Non Compliance including 'Non Compliance - Rental Accommodation Standards', 'Non Compliance - Tax Clearance Certificate', 'Fire Safety Notice';

Tenant Ends Tenancy including 'Tenant gave notice', 'Voluntary exit from HAP';

Social Housing including ‘Social Housing’;

Deceased Tenant includingDeceased Tenant’;

Miscellaneous including 'Change from Landlord/Agent for payments', 'Exceptional circumstances - Differential Rent increase', 'Exceptional circumstances - Education', 'Exceptional circumstances - Landlord Monthly Rent increase', 'Exceptional circumstances - Medical', 'Exceptional circumstances - Property Standards', 'Exceptional circumstances - change in family composition', 'Exceptional circumstances - work in different area', 'Family Composition HAP Change CAP', 'Family Composition HAP New CAP', 'Landlord/Agent Change', 'Movement within HAP after 2 years', 'Tenant Change';

Social welfare

Benefit schemes from the Department of Employment Affairs and Social Protection have been categorised into the following groups:

  • Pensions including State Pension (contributory and non-contributory), Widow’s, Widower’s or Surviving Civil Partner’s Contributory Pension

  • Working Age Income Supports including Jobseeker’s Benefit, Jobseeker’s Allowance, One-Parent Family Payment, Widow’s, Widower’s or Surviving Civil Partner’s Non-Contributory Pension, Deserted Wife’s Allowance, Basic Supplementary Welfare Allowance, Farm Assist, Deserted Wife’s Benefit, Maternity Benefit, Paternity Benefit, Adoptive Benefit, Health and Safety Benefit, Redundancy Payments, Insolvency Payments

  • Working Age Employment Supports including Rural Social Scheme, Tús - Community Work Placement Initiative, Back to Work Enterprise Allowance, Short-Term Enterprise Allowance, Part-time Job Incentive Scheme, Working Family Payment, Back to Work Family Dividend, JobsPlus Incentive, Partial Capacity Benefit

  • Illness, Disability and Carers including Illness Benefit, Invalidity Pension, Disability Allowance, Blind Pension, Carer’s Allowance, Carer’s Support Grant, Carer’s Benefit, Domiciliary Care Allowance, Medical Care Scheme, Injury Benefit, Disablement Benefit, Constant Attendance Allowance, Incapacity Supplement, Death Benefit

  • Children including Child Benefit, Working Family Payment, Guardian’s Payment (Contributory), Guardian’s Payment (Non-Contributory), Back to School Clothing and Footwear Allowance, Widowed or Surviving Civil Partner Grant, Family Income Supplement

  • Supplementary Payments including Electricity Allowance, Gas Allowance, Free Television Licence, Fuel Allowance


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