Citizenship - earliest date of application after ILR

[nnj10]

1) Eligibility - 12 months free from Immigration time restrictions after ILR which was based on Tier-1 (5 years).

Freedom from Immigration time restriction starts from the date ILR is granted i.e. you receive approval letter.
(note that there is no word to the effect that says that you are granted ILR on approval letter but says that you will receive your BRP card in post.)

2) Date of Application - According to form AN - the date of application is treated as the date application is received by UKBA (and note the date the application is posted)

Question:
Can you apply as early as anniversary of ILR approval i.e. if ILR was approved (read: letter given at UKBA PEO and not actually receipt of BRP card)
on 10-APRIL-2012, can you send your application on 09-APRIL-2013 by Special Delivery so that UKBA receives it on 10-MARCH-2013?

[Adojay]

1) Eligibility - 12 months free from Immigration time restrictions after ILR which was based on Tier-1 (5 years).

Freedom from Immigration time restriction starts from the date ILR is granted i.e. you receive approval letter.
(note that there is no word to the effect that says that you are granted ILR on approval letter but says that you will receive your BRP card in post.)

2) Date of Application - According to form AN - the date of application is treated as the date application is received by UKBA (and note the date the application is posted)

Question:
Can you apply as early as anniversary of ILR approval i.e. if ILR was approved (read: letter given at UKBA PEO and not actually receipt of BRP card)
on 10-APRIL-2012, can you send your application on 09-APRIL-2013 by Special Delivery so that UKBA receives it on 10-MARCH-2013?

Not possible for application to be received even before it is sent out. Do you mean 10-APRIL-2013 instead?

Back to the original question. If you received ILR via PEO with Approval letter dated 09-APRIL-2012. You can send your naturalization application however by post so UKBA receives no earlier than 10-APRIL-2013.

Hope this helps.