Patent dating guide
(Fees in respect of years up to and including the year in which mention of grant is published are paid direct to the EPO).Where a renewal fee becomes due within three months after publication of the mention of grant, it may be paid up to the end of the third calendar month after the month in which the date of grant falls. In addition to the renewal fee, Form 12 must also be filed within the same period (preferably at the same time).
For example, since s.19 is a provision prior to s.25(1), an application cannot be amended once a patent has been granted, but the specification of the patent cannot be amended until after publication of the notice of grant, because s.27 is a provision subsequent to s.25(1).This date is later than the date on which a patent was granted see 18.86, 24.01, and which is the date effective for all provisions of the Act prior to s.25(1).This was confirmed by the Hearing Officer in ITT Industries Inc’s Application  RPC 23 (see especially page 27 line 20 onwards).The ection applies to both patents granted under the 1977 Act and European patents (UK).A patent granted under this Act shall be treated for the purposes of the following provisions of this Act as having been granted, and shall take effect, on the date on which notice of its grant is published in the journal and, subject to subsection (3) below, shall continue in force until the end of the period of 20 years beginning with the date of filing the application for the patent or with such other date as may be prescribed. Thus the effective date of grant for the purposes of all provisions of the Act subsequent to s.25(1) is the date on which the specification of the patent was published and the notice of grant appeared in the Journal (or, in the case of a European patent (UK), the grant was mentioned in the Bulletin).