Some years ago arriving LHR in J, I went through the regular non-EU immigration line rather than the fast track, so I saved the dark pink envelope they handed out before we deplaned. My next trip is going to be in Y sadly... Am I likely to get in trouble if I try to use this envelope from a couple of years back? I have no idea what they look like now-a-days.

Thanks for any thoughts you might have!

You will be fine using it
I have quite a collection at home
Even if I am not actually going to stop in London
I save them for a time when I might be in London for a stop and am going coach
The officers will just take the now piece of paper without checking your ticket

The last 2-3 times I arrived internationally in LHR T-3 the Fast Track was useless, and the arrival queues were lengthy.

The timing to arrival is key along with the day of the week
Had some days were is wide open and then I look back and it's really long
Better than standing in the other line thiugh

Same here.. the collection at home. Have given to family traveling in coach

They can be useful to have in hand. When I travel with my kids, we get one each on the plane but only need one for the family to enter the queue. I carry a few in my passport holder to whip out when beneficial.

It has been so long since I arrived at LHR on AA, and a year since I few AA at all, I really have no idea. If so, I've discovered a cache of eight of them and three Emirates coupons in an old notebook. I'm just wondering if they're useful anymore.

EDIT:

If it matters, four are old AA logo, four are new logo.

Also wondering this. How often do they change color or format to prevent people from reusing them? I've got a new logo pink one from last December that I am hoping to use again in November if my upgrade doesn't work out.

My last few flights into LHR on BA/AA, never got one, but never needed one. Usually just flash them my Ck card, or J/F BP and its no issue.

Yes they are. Albeit with the new logo but they never seem to really pay any attention.

I think that may be the point. whether the passes are still good if OP isn't accessing via Emerald status or fare class

Sometimes works, sometimes doesn't. Sometimes they check the boarding pass in the wallet, they guard that channel pretty carefully.

Last time we used the pass at LHR we stood in "express lane" with only 7-8 people ahead of us for 20-25 minutes as the officers rotated and took their sweet time. All the while the non-express lanes processed dozens of folks.Got the feeling they were trying to send a message to the airlines or someone.

I've seen that. It's frustrating to see the "normal" queues progress faster than the "Express Lane". LHR T-3 arrival can be a true clown alley, though not as entertaining.

Second this!

In my recent 2 transit experiences in the "clown" alley, both were dreadful.

Hey JDiver, you just coined the appropriate name for it!