Stuart and Mark worked until late on Sunday to inform clients of the rule changes.
Fears are rising in the trade about family travel to Spain this Christmas because of tighter entry rules due to the Omicron variant.
The UK's largest outbound market now requires all arrivals over the age of 12 to prove they are fully vaccine free, effectively barring UK teenagers as most to date have only had one vaccine.
The UK has reintroduced tests for arrivals, while other countries have increased entry restrictions.
This week, agents and operators scrambled to contact clients in resort and those due to travel to explain the changes.
The changes for Spain are the biggest concern for this winter despite the UK government giving second jabs for 12 to 15-year-olds within three months.
The Managing Director of Designer Travel said that Spain's rules had caused an enormous problem.
She said that clients would have to wait two weeks to see if the rules change again.
The agents wanted to know how long the new rules would be in place.
Swords Travel co-directors Stuart and Mark Swords said that they were having to hold clients' hands. Guidance and information is needed as to what we can say.
The situation is very difficult for businesses, and the problem is the lack of clarity on the message for Spain over Christmas.
The lack of a time frame for when the rules will be reviewed caused the Spain change to cause a lot of cancellation. She said that the biggest concern was that it would be in place over the Christmas holidays, which is when most families will travel.
The chairman of Miles Morgan Travel said they were trying to get people to hang fire while they waited for clarification.
Chris Bailey said the situation could change in a few weeks. He said that the best thing to do was to only call people about travel.
The US is weighing tighter travel requirements for arrivals.
The impact of new travel restrictions was nothing compared to previous shocks.
