A1 certificates in social security and payroll audits

The table shows whether employers in each country are subject to social security, payroll or employer audits in which the authorities can review the social security coverage of employees who worked abroad.

This is relevant for A1 compliance because an employee may temporarily work in another country while remaining covered by the social security system of the home country.

For example, a UK employee working temporarily from Cyprus may remain subject to UK social security. The employer therefore continues paying UK National Insurance contributions during the period abroad. The A1 certificate documents that UK social security legislation continues to apply despite the employee physically working in Cyprus.

The same principle applies across the EU/EEA, Switzerland and the UK.

During a later employer or social security audit, the home-country authority may review whether continued home-country social security coverage during periods of work abroad was correct. The A1 certificate provides the evidence for that coverage.

This means that A1 compliance is not only relevant because an authority in the country of work might request the certificate. It can also become relevant later during an audit of the employer in the employee's home country.

The table works in both directions: the same authorities audit both the home-country case (an employee insured in that country who works abroad) and the inbound case (an employee working in that country while insured elsewhere, where the foreign A1 certificate proves that no local contributions were due).

For employers with employees working abroad, the practical consequence is therefore clear: where an A1 is required, the employer should obtain and retain it as part of its social security documentation for the relevant period abroad.

The audit frequency differs significantly between countries. Some countries carry out periodic employer audits, while others use risk-based selection, data analysis, complaints or specific audit campaigns. However, in each case identified in the table, the employer's social security treatment of employees may be subject to review.

Country	Audit / inspection possible?	Authority	Legal basis	Frequency / trigger, where known
Austria	YES	Tax authorities / ÖGK – GPLB	Sec. 41a ASVG; PLABG	Audit planning and specific concerns. No fixed four-year cycle.
Belgium	YES	Social Inspectorate / NSSO	Social Criminal Code, Arts. 22–49	Ex officio, complaints, authority referrals, judicial requests, campaigns or work accidents.
Bulgaria	YES	National Revenue Agency (NRA/NAP)	Tax and Social Security Procedure Code	Tax and social security controls. No fixed statutory audit cycle identified.
Croatia	YES	Tax Administration / competent social security and inspection authorities	Tax and compulsory contribution legislation	Employer and contribution audits. Specific selection criteria not conclusively verified.
Cyprus	YES	Ministry of Labour and Social Insurance / Labour Inspectorate	Social Insurance Law 59(I)/2010; Labour Inspectorate Law 88(I)/2020	Monthly targeted campaigns, complaints, proactive inspections and risk indicators.
Czech Republic	YES	Czech Social Security Administration / District Social Security Administration	Act No. 582/1991 Coll.; Act No. 589/1992 Coll.	Employer audits covering registration and social security contributions. No fixed cycle verified.
Denmark	YES	Danish Tax Administration	Kildeskatteloven Sec. 86	Document-based controls and business visits. No general fixed cycle identified.
Estonia	YES	Tax and Customs Board (MTA)	Taxation Act Secs. 73 et seq.; Social Tax Act	Tax audits may cover specific taxes and factual issues, including social tax. No fixed cycle.
Finland	YES	Finnish Centre for Pensions / pension insurance institutions	Employees Pensions Act (TyEL), Sec. 188	Statutory employer audit powers plus monitoring through income register data. No fixed cycle.
France	YES	URSSAF	Code de la sécurité sociale, Arts. L243-7 et seq.; R243-59 et seq.	Audit programmes and risk / case selection. No fixed cycle for every employer.
Germany	YES	German Pension Insurance	Sec. 28p(1) SGB IV	Every employer is audited at least every four years. Earlier audits are possible in specific cases.
Greece	YES	e-EFKA / PEKA	Law 4445/2016 and related social security audit provisions	Regular and extraordinary audits covering employer declarations, payroll and insurance treatment.
Hungary	YES	NAV	Act CL of 2017 on the Rules of Taxation and social contribution legislation	Tax and contribution audits. No general fixed audit cycle verified.
Ireland	YES	Revenue Commissioners	Revenue legislation and Code of Practice for Revenue Compliance Interventions	Risk-based. Level 2 Risk Reviews and audits may cover PAYE, PRSI and USC.
Italy	YES	National Labour Inspectorate (INL) / National Social Security Institute (INPS)	Legislative Decree 149/2015 and social security legislation	Audit programmes, targeted controls and case-specific inspections. No fixed cycle.
Latvia	YES	State Revenue Service (VID)	Law on Taxes and Duties and state social insurance legislation	Tax controls and audits. May be triggered by inconsistencies or information from other authorities.
Lithuania	YES	Sodra / State Tax Inspectorate	Law on State Social Insurance; Law on Tax Administration	Employer and social security audits. No general fixed cycle.
Luxembourg	YES	CCSS / competent social security authorities	Code de la sécurité sociale	Employer reporting and contribution compliance may be reviewed. No fixed audit cycle identified.
Malta	YES	Commissioner for Revenue / Department of Social Security	Social Security Act, Cap. 318 and tax legislation	Payroll and contribution compliance controls. Exact audit triggers not conclusively verified.
Netherlands	YES	Dutch Tax and Customs Administration	Algemene wet inzake rijksbelastingen (AWR)	Boekenonderzoek, business visits and other controls. Audits may focus on specific periods or issues.
Poland	YES	ZUS	Arts. 86 et seq. of the Social Insurance System Act	Audit planning and risk selection. Extraordinary audits are also possible.
Portugal	YES	Social Security Inspection Services	Social Security Contributions Code and inspection legislation	Employer and contribution audits. No general fixed cycle verified.
Romania	YES	ANAF	Fiscal Procedure Code, Law 207/2015, Arts. 113–119	Risk-based. General or partial fiscal inspections based on identified fiscal risk.
Slovakia	YES	Social Insurance Agency	Act No. 461/2003 Coll. on Social Insurance	Centrally prepared six-month audit plans. Extraordinary audits may follow reports or information received.
Slovenia	YES	Financial Administration (FURS)	Tax Procedure Act (ZDavP-2)	Tax audits may cover social security contributions and may be expanded if underpayment is suspected.
Spain	YES	Labour and Social Security Inspectorate (ITSS) / TGSS	Law 23/2015 and General Social Security Law	Inspection planning, complaints, referrals or other information. No fixed employer audit cycle.
Sweden	YES	Swedish Tax Agency	Tax Procedure Act (2011:1244)	Tax audits may cover employer contributions. No general fixed cycle.
Iceland	YES	Icelandic Revenue and Customs	Tax legislation and Social Security Tax Act (Act No. 113/1990)	Employer payroll and social security tax can be audited. No fixed audit cycle identified. Detailed selection criteria not conclusively verified.
Liechtenstein	YES	AHV-IV-FAK	Art. 28(2) AHVG; Art. 63(1) AHVV	Periodic employer audits by auditors with access to relevant accounting and personnel records.
Norway	YES	Norwegian Tax Administration	Tax Administration Act and National Insurance legislation	Tax / contribution audits plus automated controls of monthly A-melding data. No fixed audit cycle.
Switzerland	YES	AHV compensation funds / audit bodies	Art. 68 AHVG; Art. 162 AHVV	Statutory periodic employer audits. No fixed four-year cycle comparable to Germany; intervals depend on the Swiss audit framework.
United Kingdom	YES	HMRC	Finance Act 2008, Schedule 36 and NIC legislation	Risk-based Employer Compliance Checks. No fixed cycle. NIC treatment may be reviewed as part of the audit.