I don't know if I can apply for ILR.
The technical answer to that is .... no you cannot apply for ILR ..... ever! The better question from you would have been ... can I apply for PR? (PR being the EU-route equivalent of ILR! And it matters ... there are differences .... for example no pass required for the Citizenship Test in order to get PR!)
Sorry to say that the comment from olisun is not correct. For a start we are now talking of a 5-year period. But it is actually more complicated than that.
Up to the introduction of new EU regulations on 30.04.06 your time in the UK from when you got your business visa ..... 2003? ... would have counted towards your 5-year period. However following the introduction of those regulations on 30.04.06, your time in the UK prior to your country joining the EU on 01.05.04 no longer counts towards your 5-year EU period. Accordingly I think your will be eligible for PR on 01.05.09 .... nearly 2 years away ..... and following the introduction of those regulations on 30.04.06 you will get PR automatically on that date .. on your facts ..... even without application. Yes you can complete a form EEA3 and get a Permanent Residence sticker in your passport, but the lack of such sticker will not detract from the fact that you will have PR from the 5th anniversary of your country joining the EU.
Your reason for making this enquiry? You want to apply for Naturalisation as British? If so, your earliest date for doing that appears to be after you have had your PR for one year .... 01.05.10.
