HMRC statement of income

What to do if you need to provide evidence of your UK income when applying
for foreign health care or social security benefits.
If you live abroad and apply for health care, social security benefits or
permanent residence status, you may be asked to provide a record of your
recent UK taxable income.
Documents you can use as evidence of your UK taxable income include your
 Self Assessment tax calculation (SA302), or
PAYE (Pay As You Earn) calculation, if you receive one.
If you do not have either of these documents, or need confirmation that you
had no UK taxable income in a particular tax year in order to prove your
income for a foreign authority, contact HMRC
You can telephone +44 135 535 9022 (from abroad) and ask for written
details of:
 your taxable income in the UK for a particular tax year, or
 confirmation that HMRC have no record of taxable income in the UK for
a particular tax year.
You must state that:
 You are living or working abroad; and
 You need proof of income, or lack of it, for an overseas tax authority.
Alternatively you can make the request in writing to HMRC at:
Customer Operations
PAYE and Self Assessment
Lynx House
1 Northern Road
PO6 3XA.