Coach tour operator Bowen Travel Group has gone into administration affecting shops in Lincoln, Louth, Horncastle and Spilsby.
The Bowen Travel Group branch on Lincoln's High Street has closed, today along with the Appleby's Coach Holidays in Eastgate, Louth, the High Street in Horncastle and in Spilsby.
Appleby's Coach Holidays also has a base in Conisholme, just outside of Louth, which is also closed.
The company has 38 travel agencies across the West Midlands, Lincolnshire and Northamptonshire.
It also operates three coach holiday brands, Bowen's, Appleby's and York's under umbrella brand BGT Travel, a member of Hays Independence Group.
Customers who have booked holidays with the group will have their bookings protected under the trade body CPT scheme.
A spokesperson for the Association of British Travel Agents said: "If customers have booked a Bowen's coach holiday, their money is fully protected under the CPT Bonded Coach Holidays scheme.
"If they have booked a holiday through Bowen on behalf of another operator, Hays Travel will honour all existing retail bookings and is currently contacting these customers, along with its suppliers, to notify them about this."
It is currently unclear how many members of staff work at the Lincolnshire stores but all Bowen staff are being offered the opportunity to work from home for the Hays group.
Managing Director of Hays, John Hays said: "We are trying to contact staff to see if they want to work from home.
"We've found that in these unfortunate circumstances they can continue looking after their clients as we've got the database as we looked after the bookings.
"It works well for members of staff but also clients, as although we administer bookings from head office we would still like to have a local presence."
Any Bowen staff who are interested can call Hays on 0800 412 5990.
Mr Hays added: "We sent out letters and emails to customers about their bookings yesterday, first class, so they should be there today or tomorrow.
"If customers are concerned they can call our customer services number on our website to confirm their travel details and get reassurance."
Insolvency specialist Deloitte are understood to have applied to the courts for an administration.