Ticket holders will need to provide their COVID status to gain entry to this year's Slam Dunk Festival in Hatfield.
Music fans attending September's festival will be required to either prove they are double vaccinated, have immunity or a negative COVID test result.
COVID status must be provided for all festival-goers aged 11 and over.
The pop-punk, ska punk, emo, metal and alternative rock festival is due to return to the grounds of Hatfield House on Sunday, September 5.
Headlining the Slam Dunk Festival South 2021 line-up in Hatfield Park will be Sum 41 and Don Broco, with Frank Turner and the Sleeping Souls also on the bill.
Team Slam Dunk posted an important update about this year's festival guidelines on its social media pages.
The post read: "Much like many other festivals and large scale events across the country, Slam Dunk Festival will be asking all ticket holders to provide their COVID status to gain entry in to this year's event.
"We would like to point out that you DO NOT need to be double vaccinated to gain entry."
Providing either of the following is acceptable to organisers:
- Proof of a negative lateral flow or PCR test result logged within 48 hours of the event;
- Proof of immunity based upon a positive PCR test result, clear of the 10 day isolation period, logged within 180 days of the event;
- Proof of double vaccination, with the second dose received at least 14 days prior to the event.
The Slam Dunk statement added: "Just one of the above criteria is needed in order to gain entry.
"For negative test results, they must be logged with the NHS, and the text/email confirmation will be accepted as proof.
"We also encourage people to use the NHS App which not only shows your test results but is also the way to prove your record of vaccination or immunity through previous infection.
"Paper vaccination cards are not accepted."
Organisers added: "If you test positive or have been asked by test and trace to isolate, a refund will be available from your ticket provider.
"We'd like to thank you in advance for your co-coperation in this matter and hope you understand the necessity of these procedures in order to help us deliver the most risk-free environment for all of our customers, staff, and performers."
Slam Dunk's statement added: "Obviously, things may change before the festival rolls around in September.
"Other forms of certification may become available. We will update you on this as and when more information becomes available.
"We aren’t privy to any information that you aren’t, and are doing our best to navigate this new and unique challenge to still provide the festival you are used to.
"We appreciate all the positive and understanding messages from our great customers, and will update you as often as possible if things change. A definitive guide will be published the week of the event."
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