How do we handle PCR test req for passing through Heathrow to Eurostar (to Paris)?

I am worried because the airport in US will want to see proof that we have scheduled a PCR but we are not staying in London, we are "through passengers". If we put that on our passenger locator form, is that good enough?

EDIT- Original comment deleted as OP found answer making them moot.

Just hope the personnel at the US airport is aware of the 'workaround' UK regs contain.

Good to read you found the solution

Agreed. But it is what it is. It would have been another $4000+ to switch flights. We were originally supposed to stay in London for 3 days, but with the quarantine while testing we decided to move on. The PLF has a spot for passing through, and if we hang around we would obviously be at risk of being fined... I just don't want to be forced to purchase tests that we will not use, unless there is NO other way...

May have found my answer, this is on the gov.UK website:

Landside transit
Landside transit is when you pass through UK border control on arrival, but you leave the UK shortly after (usually within 24 hours). You may leave from the same airport, railway station or port where you arrived, or from a different one, so long as you travel directly to that port of departure.

You need to take a COVID-19 test before you travel to England.

You must complete a passenger locator form before you travel to England.

You need to do the following when you complete your passenger locator form.

select ‘Stay in the UK’ under the Your travel plans section
reply ‘I will be traveling for an exempt reason’ to the question about whether you are required to self-isolate on arrival
select the Exemption options, and then select ‘Transit Exemption’
This includes if you are transiting onto the Channel Islands or the Isle of Man. You may need to show evidence of onward travel and where you will be staying at the border.

When you are in England you do not need to quarantine or take any COVID-19 travel tests.

You must either:

remain within your port of entry until your departure from England
travel directly from your port of entry to another port of departure in England

That is helpful information. Thanks for posting it.

Yep...you found the exemption. I'm using it the other direction in a few weeks

Hi,
Please double-check, but according to this morning's new rules, you will not be able to enter France for tourism purposes after "transiting" landside and across London. Only transit in "international zone" (which I read as "airside") makes you exempt. If you do not cancel / reroute the whole trip, you should look into flights between Heathrow and Paris - availability should not be an issue, given the new restrictions.

Passengers are only deemed to be transiting a country if they have a single through-ticket.

https://www.theguardian.com/money/2021/dec/14/ryanair-refused-boarding-over-passenger-locator-form

If this is correct then Heathrow > Eurostar > Paris ain't transitting

It looks like France is limiting tourist coming from UK starting Dec 18. I don't know when your trip is?

https://www.bbc.com/news/world-europe-59679861

"*France is tightening Covid restrictions for travellers arriving from the UK, as the government in Paris tries to slow the spread of the Omicron variant.

From Saturday, most travellers who are not French residents or citizens must give a "compelling reason".*"

The French Government website:

https://www.diplomatie.gouv.fr/en/coming-to-france/coming-to-france-your-covid-19-questions-answered/article/coming-to-france-your-covid-19-questions-answered?var_mode=calcul