A British couple were denied boarding to Bali last summer. Not because they lacked a visa — they'd filled in the online form two weeks before departure — but because they'd used a third-party website that charged £45 to process an Indonesian eVisa that costs $35 and takes six minutes to apply for directly. The third-party site had applied for a single-entry tourist visa; they'd ticked the box for a 60-day stay. The Indonesian system had issued a 30-day visa. The airline checked, flagged the discrepancy, and grounded them until they could demonstrate their exit plans fell within 30 days.
Visa complications like this are among the most avoidable problems in travel — and among the most common. This guide explains how the different visa types actually work, what the documents mean, and where the system routinely catches people out.
The basic types of entry permission
Every country controls who may enter and on what terms. The mechanism varies widely, but the underlying question is always the same: does your passport, your purpose of visit, and the length of your stay meet the country's entry requirements?
Visa-free entry
The simplest case. Your passport entitles you to enter without any advance application — you present your document at the border, an officer stamps or scans it, and you're admitted for a set period (typically 30–90 days). This is the default for many Western passport holders entering EU countries, the UK, or Australia. “Visa-free” does not mean “no rules”: the officer can still refuse entry if they believe the purpose of your visit doesn't match what's permitted, or if you can't demonstrate onward travel or sufficient funds.
eVisa
An electronic travel authorisation issued in advance of your trip. You apply online through the destination country's official government portal, pay a fee, upload your passport photo and sometimes supporting documents, and receive approval by email — typically within 24 hours to five working days. On arrival you present the eVisa approval (printed or on screen) alongside your passport.
Countries that have switched to eVisa systems in recent years include India, Kenya, Sri Lanka, Saudi Arabia, and Egypt. The UK's Electronic Travel Authorisation (ETA), introduced in 2024, functions the same way for short-stay visitors to Britain who previously entered visa-free. Always apply through the official government website; third-party “visa service” sites typically charge inflated processing fees for an identical application.
Visa-on-arrival (VOA)
A physical visa stamp issued at the border itself, rather than in advance. Thailand, Cambodia, and Jordan, among others, operate VOA systems for many passport holders. You pay a fee at the visa desk, have your photo taken, and receive a stamp. The process typically takes 20–60 minutes, but during peak hours at busy airports (Bangkok's Suvarnabhumi at 11pm, for example) the queue can stretch to two hours.
VOA systems have one firm rule: bring the fee in cash, in the right currency. Many desks in South-East Asia accept US dollars but will not accept cards or local currency at the point of arrival. Arriving without the right cash means waiting at a side desk while the queue moves around you.
Embassy or consulate visa
A physical visa sticker applied to a page of your passport, issued by the destination country's embassy or consulate in your home country before you travel. Required for countries with no eVisa option for your passport, or for stays longer than the visa-on-arrival limit. The application typically requires your physical passport for a period of days to weeks, which creates a planning problem if you have other trips during that window. Most countries now offer a courier service so you can send your passport and receive it back by post rather than making an in-person appointment.
Processing times for embassy visas vary enormously. For popular destinations, allow 4–6 weeks at a minimum; for less common routes, allow two to three months. Some countries — most notably China and Russia, for UK applicants — have short appointment availability windows that make last-minute applications effectively impossible.
Transit visas: the detail most travellers miss
A transit visa allows you to pass through a country en route to somewhere else — without formally entering as a tourist. Whether you need one depends on three factors: your passport, the country you're transiting through, and whether you leave the international transit zone (i.e., clear immigration and enter the country, even briefly).
The most common pitfall is the airside transit visa, or Direct Airside Transit Visa (DATV) in UK immigration terminology. Some nationalities need permission even to transit through certain airports without leaving the plane or clearing customs. British nationals transiting through some African and Asian hubs need to check their specific route carefully; holders of certain passports transiting through the UK or Schengen Area may need a transit visa regardless of whether they leave the airport.
The practical test: if your itinerary requires you to collect your checked bag and re-check it for a connecting flight — which happens when airlines are not interlined, or when connecting across different terminal buildings — you will almost certainly clear immigration in the transit country. That makes you a visitor, not a transit passenger, and the transit visa rules shift accordingly.
Rule of thumb
Check visa requirements for every country your routing passes through, not just your final destination. A connection in Istanbul, Doha, or Addis Ababa may have its own rules depending on your passport.
How long your visa actually lets you stay
Visas come with two distinct time limits that are frequently confused:
- Validity period: the window within which you must use the visa to enter the country. A six-month visa issued in March may be valid until September, meaning you must enter before September, not that you may stay until September.
- Duration of stay: the maximum number of days you may remain in the country once you enter. Typically 30, 60, or 90 days; printed in the stamp or on the eVisa approval letter. This is the number that matters once you're inside.
- Number of entries: single-entry visas expire on use (you cannot leave and re-enter on the same visa); double or multiple-entry visas allow re-entry.
Overstaying the duration of stay — even by one day — can result in fines, deportation, a ban from re-entry, and a flag against your passport in the country's immigration database. Thailand, for instance, issues automatic fines for overstays and will detain you at the departure airport until they are paid. Indonesia introduced harsher penalties in 2025.
Where the system routinely goes wrong
Third-party visa websites
A cottage industry of unofficial “visa service” sites sits between travellers and official government portals, charging £30–£100 for an eVisa that takes minutes to apply for directly and costs a fraction of that. Some of these sites are legitimate application facilitators; many are not. The problem is not just cost — it's that third-party applications are sometimes filled in incorrectly, submitted to the wrong category, or (in scam cases) not submitted at all. Always use the official government website. For popular destinations, the official URLs are easy to find; if in doubt, your country's foreign office lists verified visa links.
Passport validity requirements
Most countries require your passport to be valid for at least six months beyond your intended departure date from their territory. A passport valid until March is effectively unusable for travel beyond September — even for a one-week trip. Airlines check this at check-in; a non-compliant passport means a denied-boarding notice and a lost ticket. Check the expiry date well in advance of booking, and renew early: British passport renewal wait times reached 10 weeks in 2025 and are unpredictable.
Children's documents
Children need their own passports for international travel in almost all cases — no more entry on a parent's passport, which was phased out years ago. If a child is travelling with only one parent or with someone who is not a parent or guardian, many countries require a notarised letter of consent from the absent parent. This is strictly enforced at borders in South Africa, Brazil, and parts of Central America; airlines may also ask at check-in. Prepare the consent letter well in advance and carry it in hard copy.
Dual nationality complications
Some countries — including Iran, Malaysia, and North Korea — do not recognise dual nationality. Entering on one passport and exiting on another, or travelling to a country that does not recognise your other nationality, can create serious complications. If you hold two passports, research the specific rules for your destination before deciding which one to travel on. The general principle: enter and exit on the same passport.
The 90-out-of-180-day Schengen rule
Post-Brexit, UK passport holders are no longer EU citizens and are subject to the Schengen Area's short-stay rules: a maximum of 90 days in any 180-day rolling window across the 27 Schengen countries. This is not 90 days per country; it is 90 days total across the whole zone. A long summer in France, a short work trip to Germany, and a weekend in Portugal all count against the same allowance. The 180-day window rolls daily, not by calendar half-year.
Overstaying the 90-day limit carries the same consequences as overstaying any other visa. The European Travel Information and Authorisation System (ETIAS) — a Schengen eVisa for short stays — has been delayed repeatedly and is now expected to launch in 2027. Until it does, UK passport holders enter visa-free but must track their days carefully.
How to check what you actually need
The definitive source for UK passport holders is the Foreign, Commonwealth & Development Office (FCDO) travel advice pages, which list visa requirements and passport validity rules by country. These pages are updated when requirements change — which happens with little notice. Check them, not a travel blog or forum post, for any trip within the next six months.
For a specific itinerary involving multiple countries or connecting flights, the IATA Travel Centre (used by airlines to verify passenger eligibility at check-in) is the most precise resource. It checks your passport type against your routing, including transit requirements.
For quick reference during the planning stage — checking whether a destination typically requires a visa for your nationality, or what the stay limit is — tools like the Farlounge packing tool can help you consolidate your pre-trip checklist so nothing gets missed in the planning process.
The practical checklist
- Check passport expiry against six-months-beyond-return-date rule for every country on the itinerary, including transit countries.
- Verify visa requirements for each country — entry, transit, and any country you enter to re-check bags.
- Apply through official government portals only. If you cannot find the official site, use FCDO or your foreign ministry's country-specific advice page as a starting point.
- Apply well in advance: eVisas within 72 hours of travel are possible but risky; embassy visas need weeks to months.
- For VOA destinations, confirm the fee in cash, in the correct currency, at the correct desk before you land.
- If travelling with children on behalf of another parent or guardian, carry a notarised consent letter.
- Track Schengen days if you are a UK passport holder visiting multiple European countries over a period of months.
- Check your travel insurance covers disruption caused by visa or documentation issues — many policies exclude this category entirely. Our guide to travel insurance explains the exclusions worth reading before you buy.
What happens if you get it wrong
Airlines bear the cost of repatriating passengers they carry who are then refused entry by immigration. As a result, check-in staff and electronic gate systems verify documents with the same database used by immigration officers — the TIMATIC system. If your documentation is non-compliant, the airline will deny boarding. This is not a negotiable conversation at the desk; it is a system flag that requires the underlying issue to be resolved.
If you are turned away at a border post rather than check-in, you will be held in the international zone and returned on the next available flight to your departure point. The cost of that return flight is yours. If you are already in a country and overstay, the consequences on exit include fines, detention, and potential bans from re-entry.
The margin for error in documentation has narrowed sharply as border systems have become more digitalised. An issue that might have been overlooked by an experienced immigration officer reviewing paper documents ten years ago is now flagged automatically before you reach the desk. Getting the right visa, for the right duration, from the right source, is simply good logistics — and it is much easier than fixing it at the airport.
If things go wrong at the gate
A visa complication that grounds you before departure may have compensation and rebooking implications under your airline's policies. Our guide on what to do if your flight is cancelled at the gate covers the rights and practical steps that apply in the first hour.