Millions of holidaymakers heading to Spain this summer are being told they could face long airport delays with the introduction of new security measures. But will we really be witnessing chaotic scenes this week?

Where did these rules come from?

European governments agreed at a summit in London last August to set up a pan-European system for exchanging passenger information. Within the next year all European Union member countries will have to introduce the policy, which will require gathering Advance Passenger Information (API) from every person before boarding - or face fines.

So why did Spain make the headlines?

Spanish authorities have opted for early adoption of new European security rules and there is concern that this will cause "airport chaos" during the country's busiest season. It was reported that airlines could face fines of up to £40,000 per flight for non-compliance.

When do the regulations kick in?

The rules have already been in place in Spain for nearly six months, since March 19, without causing any major concern. Spanish authorities said they would start fining non-compliant airlines from June 19.

So are airlines likely to be facing large bills next week?

Probably not. The Spanish authorities have since said that they will be flexible with the fines as long as airlines show they are making an effort.

What information is required from passengers?

Simply your full name, nationality, date of birth and passport number. It may come as news to most of us that these basic details haven't been officially required in the past.

Hardly complicated. Why the delays?

Hopefully, there won't be any – or, at least, they won't be as bad as originally predicted. ABTA spokesperson Sean Tipton says the media has been hyping up the worst-case scenario. If you have a machine-readable passport, all the necessary info can be collected in one swipe. However, not all airports have these machines and they currently have a three-month waiting list.

Are Spanish airports already equipped?

All the major airports already have operational machines, says the Spanish Tourist Board.

What about UK airports? How many are still waiting for passport readers?

Only half of UK airports currently have them. Heathrow, Gatwick and Stansted are among those that are already prepared.

Are the machines the only answer?

No, passengers taking scheduled flights can also use airline websites to upload their information before they go. British Airways is offering some self-service kiosks too. But the procedure could be more complicated for charter operators – owned by the big tour operators – who don't have these facilities but they are doing best to check details with customers in advance. Also budget airlines may struggle as they do not have any spare time built in to their schedules for the extra checks – however simple they seem.

What are the airlines doing to ease potential problems?

British Airways has set June 13 as its own date for meeting the Spanish authorities' requirements. It has updated its website so that customers can enter their API details in their "Manage My Bookings" section. It says it is "strongly recommend" that this information is supplied before checking in to reduce airport congestion.

EasyJet has also made changes to its website so that all new bookings to Spain will automatically request the required information.

What's the advice for customers heading to Spain this summer?

ABTA say: "We would advise customers to input their information online and, where that is not possible, check-in a little bit earlier."

And a final word of reassurance from the Spanish tourist board?

"All airports will be assisted. Britain is our number one market and we're not going to shoot ourselves in the foot."