The road an Egypt-bound paper takes
Start with the plain position, because it decides everything after it. An apostille issued in Brighton for use in Egypt is not accepted, so the short road is closed on this route. Papers going there need embassy or consular legalisation instead. That is a longer chain with a further desk at the end of it, and it changes what you order, what you pay and how long you wait for the file to come home.
Geography is the part readers get wrong first. Someone in the city tends to picture a queue somewhere in town, a form handed across a desk, and a stamp the same afternoon. In practice this road runs through a register office counter, then a post box, then a consular desk. Only the first of those three has an address you can walk to.
The only desk you can walk to
Brighton & Hove Register Office sits at Town Hall, Bartholomew Square, Brighton BN1 1JA. It holds birth, marriage and death entries for the district and issues certified copies of them. A copy ordered there is not a photocopy of your sheet. It is a new official record made from the register entry itself, so it stands on the same footing as the one you already own.
That distinction is worth more than it sounds. A file that goes into the post can be delayed, misrouted or lost, and a marriage or death record lost in transit is replaced only by starting the whole errand again. Ordering a fresh certified copy for the journey keeps the sheet in your drawer exactly where it is, and the copy does the travelling in its place.
The certifying desk has no counter
The Legalisation Office (Foreign, Commonwealth & Development Office) is the body that certifies British public papers for use abroad. It is reached at PO Box 6255, Milton Keynes MK10 1XX, and it works by post. There is no public counter there, and none in this city either, so no part of that stage can be done face to face however urgent the deadline feels.
Its published charge is £45 per document by standard post, or £40 per document on a next-day service open to registered businesses. The charge attaches to each separate paper rather than to the envelope. A bundle of four sheets is four charges, not one, which is why the count of papers matters more to your budget than the weight of the parcel.
What a postal road changes about your plan
Because nothing on the British side happens across a counter, your own hours go almost entirely into preparing paper rather than travelling to it. The gap between posting and return is dead time, and turning up somewhere will not shorten it. Once you accept that shape, the route stops feeling unpredictable and starts looking like a sequence of waits you can actually schedule around.
It also means the file spends real days away from you, in both directions, before the consular stage has even begun. So knowing what you need for an apostille for Egypt is less useful than knowing what the longer road wants, which is the same properly certified sheet plus one further mark on top of the British one.