KARFA

What are the rules and restrictions?
Cancellation penalties and stopover fees change from fare to fare and from country to country, although stopovers are usually Euro 200 each-way if you break your journey in London for > 24 hours. Also remember you need to factor in the cost of getting to your point of departure, and potentially the cost of a hotel if you are travelling too far to return in a day (e.g. Cyprus, Athens).

In general, you will see the rules are much more flexible for the equivalent fare bucket ex-UK.
A neat trick for the Club fares – if you time your arrival into London and the departure of your long haul segment right, you can essentially have a free nightstop in London without having an 'official' stopover. For example, you arrive from AMS on a Monday at 21:15 and you can then book your long haul flight the next day (Tuesday) at any time up to 21:14 (< 24hrs) and it is NOT charged as a stopover. Book it for 21:15 or later and that'll be much more expensive fare please. Similarly, you can introduce overnight stays at intermediate connecting cities so long as your connections remain under 24 hours.

Note: BA seem to have clamped down on stopover rules, potentially in light of more widespread use of ex-EU fares. Check your fare rules carefully as lots of fares now limit you to a month’s stopover in the UK at most in either direction.

Fare rules
Fare rules contain all the restrictions and requirements for a particular fare. Most importantly they list things like travel dates, minimum stay, book by dates etc. The full rules of a fare can be viewed in Expert Flyer, in itamatrix, and on some airline sites like aa.com. Once you book with BA there is nowhere on BA.com that displays the fare you are actually booked under. You can try working it out from using Expert Flyer and setting the ticketing date for when you booked, or alternatively try looking up your booking at classic checkmytrip at the link below:

https://classic.checkmytrip.com/plnext/XCMTXXNS/StartOver.action;?LANGUAGE=GB&SITE=XCMTXXNS

Upgrading Using Avios (UuA) & Gold Upgrade Vouchers (GUF)
A quick note on doing UuAs is that you can do these for exEU itineraries (or you can apply a GUF if you have any). The following restrictions for UuAs apply though:

Summary guide to bookings which can be upgraded with Avios:

• BA issued tickets (can include other carriers) ^
• TA issued (on BA stock) booking with only BA flights ^
• TA issued (on BA stock) booking with other carriers
• Tickets issued on non-BA stock

The rules have previously said that the TA has to issue the ticket in the country of your BAEC membership as well. However, apparently this is not enforced consistently so hopefully this shouldn't be an issue. See these two posts for more information on that point https://www.flyertalk.com/forum/29280847-post33.html & https://www.flyertalk.com/forum/29282377-post38.html

A BA Holiday booking (flights & hotel) is UuA'able and treated as a TA booking, so a booking including non BA flights could not be UuA'ed. Also a BA Holiday booking which was made using a TA can not be UuA'ed.

Note that even if booked direct with BA on a 125-... ticket you can't UuA BA marketed and AA operated flight. The BA flight must be both BA marketed and operated.

There is more information on UuA'ing TA bookings here.

What you pay to UuA/GUF
As well as using the avois/GUF there may be an additional cash cost upgrading from one cabin to another. The costs for using a GUF are the same as the costs as if you are Upgrading using Avios (UuA).

Generally there is an extra cash charge going from WT+ to CW and WT to WT+, but no/minimal charge from CW to F. If using a GUF on short haul there would be a charge going from ET to CE. In all cases there is no change fee to pay when applying a GUF to an existing booking.

WT to WT+
From WT to WT+ there isn't any additional carrier surcharge. There may be additional APD in some cases though. For example, the APD for a WT class return from LON-NYC currently (2017) is £75, whereas the APD for a WT+ class return on the same flights is £150. As the APD is payable for leaving the UK and not arriving, the extra APD would only be charged if your GUF was applied to upgrade the flight outbound from the UK from WT to WT+. If your GUF only applied to the flight inbound to the UK there is no extra APD to pay.

When upgrading from WT+ to CW you should be paying the difference in carrier surcharge - there isn't a tax difference. The carrier surcharge applicable is route specific, generally though the longer the route the more the surcharge. For example starting from the UK the additional surcharge for CW over WT+ for a return to NYC is around £110 so the cash cost when applying a GUF should be in the region of £110 for a return.

A complicating factor is the relatively new WT+ Dual Inventory Fares (DIF) which have appeared from around mid-2016. They are a new type of fare to BA which effectively is a promotional upgrade from WT to WT+ except the cost of the upgrade is included in the booking. Whilst there is no reason you can’t apply a GUF to a DIF fare, you may find the additional cash cost in doing so is a bit more than usual For example, a normal WT+ to CW upgrade LHR-BOS return may be around £90 but for a DIF fare can be more like £160.

There is more discussion of DIFs in the thread linked to below:
Dual Inventory Fares - Is there an idiot's guide anywhere?
Why can't I find this ba.com fare on ITA Matrix?
http://www.flyertalk.com/forum/briti...ount-code.html

CW to F
For an upgrade from CW to F there is no difference in carrier surcharge, fees, or APD. Any cash charge should be zero or minimal.

ET to CE
When upgrading from ET to CE on a flight there may be additional APD. As the APD is payable for leaving the UK and not arriving, the extra APD is only payable on the outbound flight leaving the UK, and currently (2017) the extra APD due going from ET to CE is £13 per person. If your GUF only upgrades a flight in to the UK there is no extra APD to pay.

All cases
In all cases any changes in taxes, charges for customs, immigration, carrier surcharge, airport service fee, passenger service charge which have happened since the original booking was made will be taken in to account. Where these charges are priced in a currency different to what you are using to pay there may also have been exchange rate changes which change the amount needed. This really only become significantly relevant if there is a large time period in between originally making the booking and subsequently applying the GUF, and even then this recalculation of charges is unlikely to amount to more than a few pounds at most.

Maximum Permitted Mileage & Allowed Routings
MPM is often specified for fares between two point essentially to stop you going a bit too crazy on the routing. For example a DUB-JFK fare may have a MPM which either prevents you or at least imposes hefty surcharges if you try and route to JFK via the west coast.

If you are interested in understanding this further here are some posts made by those in the know:

http://www.flyertalk.com/forum/briti...merica-23.html
http://www.flyertalk.com/forum/26107663-post302.html

In addition to MPM, there may be routing restrictions on the fare which mean you can only use the fare on certain limited routings between the departure and destination airports. Routing tables can be found in Expert Flyer in the Fare Information section.

For example, the current AMS-BKK BA INCEU60 fare only allows the following routings, and if you try anything else you would not be able to price it under this fare:

1. AMS-LON-BKK
2. AMS-LON-HKG-CX/HX/RJ-BKK
3. AMS-LON-KUL-BA/MH/RJ-BKK
4. AMS-LON-SIN-3K/CX-BKK

Dual Inventory Fares
These relatively new DIF fares have appeared from around mid-2016. They are a new type of fare to BA which effectively is almost like a POUG except the cost of the upgrade is included in the booking. They seem to be appearing mostly when purchasing WTP seats, and need inventory in both an economy and premium economy booking class. There have been difficulties with the fare mostly around attempting to upgrade in to CW using a GUF or by UuA.

When DIFs first appeared there were some comments that they could only be booked direct with BA and could not be booked with a TA. However, this seems to have changed and TAs can access DIFs now.

There is more discussion in the linked posts:
Dual Inventory Fares - Is there an idiot's guide anywhere?
Why can't I find this ba.com fare on ITA Matrix?
http://www.flyertalk.com/forum/briti...ount-code.html