Form	Purpose	Issuing authority and use
A1   (formerly   E 101   E 103)	Statement of applicable legislation. Useful to prove that you pay social contributions in another EU country – if you are a posted worker or work in several countries at the same time.	The form is issued by the social security institution you are registered with in your home country.
S1   (formerly   E 106,   E 109   and   E 121 - still issued by some institutions)	Certificate of entitlement to healthcare if you don't live in the country where you are insured. Useful for posted workers, cross-border workers, pensioners and civil servants and their dependants.	Contact your health insurance authority to find the relevant institution issuing the S1 Submit it to any health insurance authority in the country where you live.
S2   (formerly   E 112)	Authorisation to obtain planned health treatment in another EU or EFTA country. You should be treated the same as a resident of that country - you may have to pay a percentage of the costs up front.	Health insurance authority Submit it to the health insurance authority in the country where you go for treatment.
S3	Certificate of entitlement to healthcare in your former country of employment. Useful for retired cross-border workers who are no longer insured in their former country of employment.	Health insurance authority Submit it to the health insurance authority of the country where you used to work as cross-border worker.
U1   (formerly   E 301)	Statement of insurance periods to be taken into account when calculating an unemployment benefit.	The form is issued by the public employment service or the competent social security institution in the last country(ies) where you worked. Submit it to the national employment service in the country where you wish to receive unemployment benefit.
U2   (formerly   E 303)	Authorisation to continue receiving unemployment benefit while looking for a job in another country.	The form is issued by the public employment service or the competent social security institution in the country where you became unemployed Submit it to the national employment service in the country where you are looking for a job.
U3	Circumstances likely to affect the entitlement to unemployment benefits. It informs the employment services of the country paying your benefits of changes in your situation which may lead to a revision of your benefit payments.	Public employment service of the country where you are looking for a job on the basis of a U2 form.
DA1   (formerly   E 123)	Entitles you to receive medical treatment under special conditions reserved for accidents at work and occupational diseases in another EU country.	Health insurance authority. Submit it to the health insurance authority of the country where you stay.
P1	The summary of pension decisions provides an overview of the decisions taken in your case by the various institutions in the EU countries from which you have claimed an old age, survivors or invalidity pension.	Pension authority to which you made your pension claim. It will deliver it once it has received details of the decisions made by the various authorities who have dealt with your claim.