Explainer

The BA 355-Day Booking Window

Reward seats appear exactly 355 days before departure. Here is precisely when that is, why it trips people up, and how to be first in the queue.

Last updated: September 2026 6 min read

The 355-day window is the single most important date in Avios booking — and the one most people get slightly wrong. Get the timing right and you are first in line for the best seats; get it wrong by a few days or a single hour and you stare at an empty screen.

1. The 355-day rule in one line

British Airways loads its schedule — and its guaranteed reward seats — 355 days before the date of departure, at midnight GMT. That single moment, often called “T-355”, is your first and best chance to grab a reward seat on a popular route before it disappears.

Want the exact date for your trip? Our reward seat release-date tool counts back 355 days from your departure and tells you how many days away it is.

2. Why 355 days and not a round number?

Many airlines open booking 360 or 361 days out, so BA’s 355 can catch people off guard. The exact figure is simply how far ahead BA loads its schedule; there is no deeper logic to memorise beyond “just under a year”. What matters is the practical consequence: if you count a clean 12 months ahead, you will be a few days too early and see nothing.

It also means the window is a moving target. Each day that passes, one more day of the calendar becomes bookable. If your ideal date has not opened yet, it will — simply check back, or set an alert, until T-355 arrives.

3. The exact timing: midnight GMT, or 1am in summer

Seats load at midnight GMT. During British Summer Time (from late March to late October) the UK clock is one hour ahead of GMT, so the release effectively happens at 1am UK time. Set your alarm for the correct UK-adjusted moment — a common mistake is to wait up for “midnight” in summer and miss the release by an hour.

Placing a seat in your online basket does not remove it from sale. Until you finish entering passenger and payment details, anyone — or a phone agent — can take it. For the most contested seats, speed at checkout genuinely matters.

4. Outbound and return open on separate clocks

Only the outbound leg becomes bookable at T-355. The return date opens 355 days before it departs — so for most round trips you book the outbound as a one-way first, then add the return a few days later when it opens.

  • Book the outbound as a one-way. Secure the harder-to-get direction the moment it releases, rather than waiting for both dates to align.
  • Add the return when it opens. On US and Canada routes especially, call BA to add the return to the existing booking so you avoid a one-way surcharge.
  • Watch both release dates. Each leg has its own countdown — our release-date tool shows both at once.

Give yourself the best shot at T-355

The British Airways Amex Premium Plus companion voucher unlocks extra Club World reward seats at release that other collectors simply cannot see — a decisive edge on the most popular routes.

Our pick for tier points

Amex British Airways Premium Plus

  • 2-4-1 Companion Voucher usable in any cabin — including Club World and First
  • Voucher valid 24 months after £15,000 annual spend
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Runner-up

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  • Earn 1.5 Avios per £1 on all spending
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Affiliate link — we may earn a commission at no cost to you. Full disclosure.

5. What is guaranteed at release

On long-haul flights, BA commits to a minimum number of reward seats the instant the window opens:

CabinHeathrow / GatwickLondon City
EconomyAt least 8At least 2
Premium EconomyAt least 2
Business (Club World)At least 4At least 2
FirstNot guaranteed

Partner airlines run their own clocks — some oneworld carriers load inventory 330 to 361 days out. See our partner award availability guide for the differences.

6. Strategies for a T-355 booking

Call the US line at midnight GMT

The UK call centre is usually closed when seats release. Many experienced collectors call BA’s US line, where an agent can hold a seat — removing it from inventory instantly — while you confirm.

Have everything ready in advance

Be logged in, with passenger details and payment saved, before the clock strikes. Every second at checkout counts on a contested route.

Missed it? Don’t panic

Seats reappear through the year as BA reviews demand and other travellers cancel. There is no waitlist, so a standing alert on your route is the smart move — see how far in advance you can book.

Frequently Asked Questions

The AviosArcana Editorial Team

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