British Airways' offer to match the frequent flyer status of those on rival airlines like Delta and United ends on Tuesday night. 

Top-tier members of eight loyalty programs can get gold or silver status on BA's Executive Club for free for at least six months under the offer.  

That grants access to the airline's posh lounges and other perks.

But it also offers something that US flyers might value more - access to American Airlines' lounges even when flying domestically in economy. Even those with AA's top status don't get that perk. 

Those wanting to take up the offer need  to live in the US and to apply by midnight ET on Tuesday, May 7. 

See below for full list of airlines, what status is needed for each plus a separate box with the five steps to sign up.... 

Gold and silver status on BA gives access to the British flag carrier's lounges, extra free baggage, priority check-in, security and boarding and a better chance of upgrades.

It also unlocks the same perks when flying on more than a dozen other airlines that are part of the same Oneworld alliance as BA, including American, Alaska, Cathay Pacific, Quantas, Qatar and Fiji. 

It is very rare for BA to match status - since getting gold involves spending tens of thousands of dollars on flights and provides enviable perks.

BA will match status with three programs from US and Canadian airlines - Delta’s SkyMiles, United's Mileage Plus and Air Canada's Aeroplan.

Members of loyalty schemes from five European airlines can get gold or silver too - Virgin Atlantic, Air France, KLM, Luthansa and Scandinavian.

The offer, launched on April 9, is valid for new and existing BA Executive Club members who hold a membership of one of the programs listed above with the corresponding status.

Customers with top tier status on the eight airlines can apply online.

They need to provide a valid proof eligible frequent flyer status, and the outcome of the application will be shared via email.

Successful applicants will be upgraded to the matched tier for an initial six-month period.

This can be extended to a full year if they book two eligible flights (or one return flight). 

An eligible flight is a BA-marketed flight in business or first class – operated by British Airways, American Airlines, Iberia, Aer Lingus or Finnair - that originates in the US, Canada or Mexico.

Full terms and conditions are here on the BA website.