1. A referendum on the UK's membership of the European Union will be held on 23 June.
2. If you were on the electoral roll in the UK within the last 15 years, then you can register as an overseas voter and have your say. #yourvotematters.
3. If you last lived in England, Scotland or Wales, go to www.gov.uk/register-to-vote and fill in your data. All you need is your National Insurance number, passport details and date of birth. (Even if you don't have an NI number, you can still register).
4. Choose how you want to vote – by post, proxy, or even in person if you will be in Britain on polling day. If you choose to vote by post, ballot forms will be despatched about one month ahead, giving you time to receive, complete and return your vote.
5. If you were last registered to vote in Northern Ireland, download an overseas voter application form from the Electoral Office for Northern Ireland, at www.eoni.org.uk. You can choose to vote by proxy or in person, but not by post.
6. Do register now, don't wait until the last minute and miss the deadline. Thousands of expatriates are already doing signing up. If you wait, you may miss your chance to have your say.
7. Just as in the UK, you need to register annually. So if you registered as an overseas voter for last year's General Election, you still need to renew ahead of the EU referendum.
8. Out of 283,000 Britons officially resident in Spain, just 11,000 were registered to vote in last year's UK General Election. Many British expats could miss out on their say in the EU referendum, so tell your friends to register too.
9. Use Facebook and Twitter to pass the message on that #yourvotematters.
10. Go to www.gov.uk/register-to-vote - make sure you can have your say