Prior to entering the country, British citizens need to apply for a visa.
Among the requirements for a visa are the following:
You must thoroughly and accurately fill out a visa application form. Your passport must be valid for at least another six months upon entering Eritrea. You will also need two recent passport photographs.
You may also need to present proof of health insurance coverage and even a reference letter from your employer stating that you are on a leave of absence and will return after vacation. Proof of hotel booking, return ticket, and funds to support your stay in the country will also be necessary.
A visa fee is also applicable.
Eritrean laws are very strict when it comes to overstaying, so make sure that you only stay within the validity of your own visa. Foreign currency should also be declared prior to entry, and anything spent in the country must have a receipt. Failure to comply with the regulations may cause in penalties and delay of departure from Eritrea.
Yellow fever vaccination, if coming from infected countries, is also a requirement prior to entry.
These terms are subject to change, and it would be best if you contacted the embassy for more queries and to confirm the requirements prior to application:
96 White Lion Street
Telephone: (020) 7713-0096