Job Retention Scheme claims portal and calculator now live

HMRC’s Job Retention Scheme claims portal is now open:

https://www.gov.uk/guidance/claim-for-wages-through-the-coronavirus-job-retention-scheme

... there’s also a new calculator to help employers work out how much they can claim in respect of furloughed workers:

https://www.tax.service.gov.uk/job-retention-scheme-calculator

So far so good:

Service availability

Full service available.

Planned downtime

None.

https://www.gov.uk/government/publications/coronavirus-job-retention-scheme-service-availability-and-issues/coronavirus-job-retention-scheme-service-availability-and-issues

British Chamber of Commerce rep on Radio 4 just said it is a one-hit application with no possibility to revise submission and no confirmation email is sent so they recommend taking a screenshot of the acceptance screen.