The NHS COVID Pass service is now available to 12 to15 year olds, accessible via NHS.UK for those aged 12 years old and over, and the NHS App for those aged 13 years old and over. This is an addition to the letter service via 119 that was launched in December last year.
Both the digital and letter NHS COVID Pass are widely accepted for international travel. It provides a record of all COVID-19 vaccinations received, with the COVID Pass showing evidence of recovery for 180 days following a positive test. Make sure you check the entry requirements of the country you are visiting as requirements for testing and vaccination can vary from country to country.