All participants are kindly requested to pre-register by sending a completed Registration form using the link to the on-line registration system: or by just pressing the REGISTER button.
Please kindly bear in mind that each participant should create his/her own account with username and password.
On-site registration will not be possible.Please, find below the conference fees with respective deadlines:


(VAT included)
Early bird
(before June 20th)
(after June 20th)
TSOP member 350 400
TSOP non-member 400 460
Student 260 340
Online participant 190 190
Accompanying person 140 180

Regular participant fees /TSOP Member, TSOP Non-member and student/ include: access to scientific and poster sessions, coffee-breaks, lunches, reception, delegate’s kit, program and abstract book.

The fee for online participation includes virtual participation in the conference, publication of the contribution, conference attendance e-certificate.

Accompanying person’s fee includes: access to reception, Sofia sightseeing tour with a visit to Boyana church, Rila Monastery one-day tour, badge.

The conference fee does not include individual costs for travel, accommodation and personal insurance.

TSOP provides two Students awards designed to support their attendance at the TSOP Annual Meeting. You can find more information on the following links:

Please note that all registrations must be accompanied by payment of the fees in EURO.
Bank transfer
Bank details can be found in the online registration platform on the last step of the process.
Please indicate the name of the participant on the bank transfer slip.
Credit card
Only Visa and MasterCard are accepted.

A letter of confirmation will be sent to participant on receipt of the registration form and respective payment.

Upon arrival in Sofia, participants will be kindly requested to visit the Registration Desk located at the Sofia University - Conference venue. Registration Desk will operate throughout the Conference. Participants will receive badges and all conference materials at the Desk. Outstanding balances for accommodation, transfers and/or tours should be settled at the Registration Desk.

Notifications of cancellations must be sent by email to Mrs. Mira Bonova /
  • Before June 30th, 2021 – 100% refund (excl. 40 Euro administrative fee)
  • Before July 30th, 2021 – 50% refund (excl. 40 Euro administrative fee)
No refunds will be given after July 30th, 2021 or for no-show.

In case of Conference cancellation due to COVID-19 all payments will be fully refunded less 40 Euro administrative fee.