The two main one’s are (ABTA) Association of British Travel Agents and (Atol) Air Travel Organisers Licensing .The main difference being that any operator selling holidays with flights must be a member of Atol which is operated by the Civil Aviation Authority .It is not compulsory to belong to ABTA but 90% of UK travel agents are members.
OK what added security do they offer you the traveller, both have bonding plans Atol’s basically cover all flights and journeys booked through a member, be that a tour operator or travel agent. Abta covers the remainder. Both protect you if the travel company fails.
This also covers UK holiday makers who have booked a coach holiday with an Abta member, should the coach company fail then you are covered by it’s bond.Always ask before you book if they are members of Abta.
So if you book your package holiday with a travel firm, because they are offering flights then you would be covered in the event of failure as they must be a member of Atol.Even if you were to book using an Internet agency and booked your flight, accommodation, car hire separately you would still be covered by the Atol bond in case of failure.
An exception to the above is if you used an airline ticketing agency which issued you with a ticket straight away then your not covered.
Now what makes all the above a bit of a farce is if you buy your ticket direct from an airline and the airline goes to the wall you are not covered . It would be unlikely that your travel insurance would cover this.
I would advise when booking any type of holiday use your credit card because under section 75 of the consumers credit card act you should be covered should anything go wrong with the airline or holiday company that excepted your card. But be aware because this would only cover ticket price’s over £100 and that is each individual ticket so you would not be covered with many low cost flights.
If you book your holiday accommodation separately and you used your credit card and the overall price was over £100 and paid for it in one transaction and something went wrong with the accommodation then you should be able to obtain a refund from your card company, please note this does not mean if you did not like your accommodation.
The same would be true if you paid for car hire and your bill was over £100 if you arrived to find no car company you would be able to get reimbursed from your card company.