Will they send me a letter requiring me to leave the country within 30 days? Or will this only affect future visa applications?
As an EU citizen, what will UK authorities do if I overstay my 6-month visitor visa by a few days?
2Do you actually have a visa or just a leave to enter for the standard six months?– Mark JohnsonJan 29 at 21:40
1@Robert007 EU citizens can normally enter the UK visa-free as a visitor, ie they are given leave to enter at the border. travel.stackexchange.com/questions/69164/…– TravellerJan 29 at 22:17
8How would they know where to send the letter? Why would they tell you to leave within 30 days instead of immediately when your presence in the UK is unauthorized?– phoogJan 30 at 3:13
15Judging by your previous question, you've already overstayed by almost a month.– Jack AidleyJan 30 at 10:49
6A few weeks is definitely more serious than a few days.– Mark JohnsonJan 30 at 11:07
Will they send me a letter requiring me to leave the country within 30 days?
The UK cannot know for sure whether or not you've left the country as you could've traveled to Ireland overland without this being recorded anywhere. So they won't be sending out letters, unless you happen to get caught in a random document check, which is quite rare.
Or will this only affect future visa applications?
It will affect both visa applications and future attempts to enter the UK. It can also jeopardize your future travel to countries like Canada, Australia, US, New Zealand, etc, which ask about prior refusals when applying for electronic authorization to travel there.
My general advice is... do not overstay. I understand this might seem like a reasonable course of action right now, but this is a good way to mess up your future travels. Leave before the 6 months period and don't violate immigration laws during your stay. If you're worried about re-entering the UK if you leave right now and immediately try to come back, you can choose to travel to the UK via Ireland which all but guarantees you entry into the country. See my answer on a related question for details.
See the OP’s previous question travel.stackexchange.com/questions/178404/… Jan 30 at 8:38
The "related question" is from the same OP Jan 31 at 13:34
The general (unofficial) rule is that you should only return to the UK after spending the same amount of time outside of the UK as the time spent on your previous visit (which may be less than the granted leave to enter).
Immigration Rules - Immigration Rules Appendix V: Visitor - Guidance - GOV.UK
Genuine visitor requirement
V 4.2 The applicant must satisfy the decision maker that they are a genuine visitor, which means the applicant:
(b) will not live in the UK for extended periods through frequent or successive visits, or make the UK their main home; and
An existing leave to enter is not effected by a stay in the Republic of Ireland. (CTA rules: Exemptions from deemed leave on the basis of specific status).
It is up to the discretion of the Immigration Officer to grant a leave to enter.
Even if you do not overstay by a few days, any return before 6 months may be denied since it would look as if you are trying to stay for a prelonged period after just spending 6 months in the UK.
Returning after 7-8 months, the Immigration Officer may see the overstay of a few days but may choose to ignore it if they have the impression you are not trying to stay for a prelonged period.
The situation would change if you were found in the UK while overstaying.
That would have a serious effect on any future reentry.
2The general (unofficial) rule is that you should only return to the UK after spending the same amount of time outside of the UK as the time spent on your previous visit — uh-uh? So if I spend two weeks in Belfast I can't make a day trip to the Republic, because I'd need to spend two weeks in the Republic before I can return to the UK?!– gerritJan 30 at 8:12
@gerrit For entering the UK from the Republic of Ireland (Common Travel Area) there are special rules. Jan 30 at 8:17
2I think gerrit's point is that the rule is surely more complicated? I.e. a 1-week trip followed by 1 day in France, followed by another week in the UK is surely OK. I'd say following something like "not more than 6 months in any 12 months period" should be a better rule of thumb.– JonathanReez ♦Jan 30 at 8:32
1@gerrit Making a day trip to the Republic after spending two weeks in Belfast is what a genuine tourist might do. Spending 6 months in the UK with a day trip to the Republic at the end would be a very different scenario. As I’m sure you know, the UK doesn’t have a strict ‘x days out of y days’ policy so the accepted norm is as described in the answer. Used with some commonsense Jan 30 at 8:32
2@JonathanReez Important is that the Immigration Officer thinks that the visit, accourding to the rules, is legitimate. The amount of time is secondary. A 2 day stay in Paris in between will cause no problem. Jan 30 at 9:44