Interlining
 

Interlining, that is multiple carrier journeys, is similar to codeshare journeys and many of the same rules apply (Resolution 302 – see the Wiki on Checked baggage allowance for details).

What is my baggage allowance?
The IATA rules use the same Resolution 302 rules as described in the Wiki on Checked baggage allowance. The Most Significant Carrier rules apply but where a carrier has different baggage allowances for different sectors the Most Significant Carrier rules are supplemented by similar Sector rules. Using the Resolution 302 rules find the Most Significant Sector of the most significant carrier and you have your baggage allowance.
Remember that unlike codeshare it is the Operating carrier not the Marketing carrier that is to be used.
Even though it is now outdated looking at http://www.frugalhack.me/2015/03/27/...w-to-use-them/
you can read “You’ll need to make sure the weights and sizes follow every airline’s rules that you plan on interlining the baggage to.” This is from early 2015 and IATA have changed the rules since then. But it is still worth thinking about especially if the journey involves a carrier with no free baggage allowance since no free baggage allowance appears to be a weakness in IATA Resolution 302.

Who interlines with who?
KVS publish lists of airlines that interline. An example for UA is shown below. Note this list is just an example and is about three years old and will have changed since then.

ELECTRONIC INTERLINE CARRIER AGREEMENTS-UA
INTERLINE CARRIER CODES
AA - AB - AC - AF - AH - AI - AM - AR - AS - AV
AX - AY - AZ - A3 - A9 - BA - BD - BE - BI - BR
BT - BW - CA - CI - CM - CO - CX - CZ - C5 - DL
EH - EI - EK - EL - EN - ET - EV - EY - FB - FI
FJ - FM - FV - FW - FZ - F9 - GA - GF - G3 - G7
HA - HU - HX - IB - IQ - JJ - JL - JP - JQ - J2
KA - KC - KE - KF - KL - KM - KQ - KS - KU - KX
LA - LG - LH - LO - LP - LR - LW - LX - LY - MD
ME - MF - MH - MI - MK - MQ - MS - MU - NH - NQ
NU - NZ - OA - OH - OK - OM - OO - OS - OU - OZ
PG - PK - PR - PS - PX - PZ - QF - QR - QX - RJ
RO - SA - SK - SN - SQ - SU - SV - S2 - S5 - S7
TA - TG - TK - TP - T0 - UL - UN - UO - UP - US
UX - VA - VK - VN - VS - VW - WF - WM - WP - WS
WY - XE - XF - XJ - XL - ZH - ZK - ZW - 2V - 3M
4C - 4M - 4Q - 7H - 9E - 9K - 9L - 9W
Oneworld changed its interlining rules this year and airlines are no longer required to interline baggage on separate reservations. Note that it is not forbidden to interline across reservations but it is no longer given that it will be done. Within a reservation it should always be done.

What if I cannot interline my baggage?
If through checking of baggage is not possible then it needs to be checked in again at some point of the journey. This usually requires that you go through the usual arrival procedures, collect your bags and check-in again. And this in spite of the fact that you already have your onward boarding pass! In some airports the transfer desk can retrieve and relabel your luggage. (DOH, CMB and sometimes BKK). There are probably many more but I do not know which

(Under development – more to come – your suggestions welcome.)

Reserved for further expansion of interlining information or rule changes.

Just had a very positive experience with this. Itin was BOS-DOH-CMB on one QR ticket, followed five hours later by CMB-BKK on UL on a different ticket.

When I checked in at BOS, I asked if the bag could be checked through. Interestingly, the UL itin was in the QR computer, -- perhaps because of the QRPC number? I was unaware that that ever happened. (I booked the UL flights directly on the UL website, not on QR's website.) In fact, it's never happened to me before.

Agent said sure, no problem. Bag tag printed with all three flights. Picked up my bag on arrival at BKK. Easy Peazy!!

In early June QR interlined my bags out of Male onto a UA flight connecting in Oslo, separate reservation, without even blinking.

Had QF BNE SYD BKK with separate QR PNR BKK DOH NBO all in J. QF refused to interline so had to collect bags at BKK, get a room at the Novotel for 6 hours for the QR counters to open :(

I have a CX booking in my QR Manage Booking page. Can only be because I entered the PC number when booking on the CX website.

Recently the check-in agent in BKK had no issue with interlining my bag from QR to AF at CDG - unfortunately, despite a 5 hr layover, AF still managed to misconnect the bag.

roadwarriorafrica it may have been worth a try to get the transfer desk at BKK to retrieve and relabel your luggage. I seem to remember that some months ago someone did just that from QR to Bangkok Air. I am not absolutely sure of this but it is worth checking. I would imagine that the more you do in the way of OLCI for your QR legs the more likely the transfer desk will deal with your baggage.
This does not help you with that trip but it may do on future trips and hopefully others will try the same. (Anything to avoid immigration in BKK!)

I was told by a QF agent in MEL last week that the rules had changed but she said she'd check my bag through on this occasion as the "rule is still new".

MEL-SYD QF (ticket 1)
SYD-DOH-OSL QR (ticket 2)
OSL-LHR BA (ticket 3)

Of course, BA manged to be the weak link in this itinerary. Despite the flight being delayed by a couple of hours they weren't able to get our bag loaded. It turned up to our house yesterday via courier...

Interestingly, when we spoke to QR in SYD they were adamant that there was no way they could tag our bags all the way through... until I explained that the bags had already been tagged and all Qatar had to do was acknowledge them during our check-in. The check-in agent mumbled something about QF having 'different systems' and told me that they shouldn't have checked my bag through.

Or maybe QR's baggage handlers sent it in to arrivals with the rest of the luggage and it got dizzy going around the conveyor belt for a few hours! I think it's unfair to always blame the final airline in an itinerary, it is not always their fault that the bag isn't loaded (although it can of course sometimes be down to them).

QR themselves are far from perfect when it comes to baggage handling, even at their home base. I've made connections, while they have been happy to leave my luggage behind (travelling J).

CX have just announced that from 2017 they will check baggage through to the final destination where there is more than one reservation (PNR) provided it is a OW carrier.
In other words they are ignoring the OW baggage rule changes of June this year.
Well done CX! Let us hope that QR will soon follow the lead.

Anyone managed to interline on separate tickets lax-doh-bkk with mh or Cx to sin?

I have a QR award DOH-DXB then QF award on EK DXB-LGW they are seperate PNR.

Will QR interline the baggage?

VH-RMD since 1 March yes QR will interline your bags with QF. I am not certain but I think that the other way around QF will still not interline with QR.

Thanks, my concern is that even though it is a QF award, it is an EK flight number....

I shall hope that the lovely people at the First check-in in Doha are feeling helpful that day.

Yesterday QR interlined my luggage with Egyptair on separate PNRs.

Everything went fine.