A total of 1,690 dog incidents have taken place, compared with 2,445 in 2019/20.
Although this is a significant drop, the postal company has described the number of attacks as “still too high.”
Most dog attacks take place at the front door but some take place in gardens, driveways or through letterboxes.
But the sudden fall in attacks has been attributed to changes in deliveries because of the Covid-19 pandemic.
Royal Mail’s contact-free delivery service in the pandemic has enabled workers to take letters and parcels to the doorstep.
It also launched its annual Dog Awareness Week with a plea to owners to ensure they understand the often “devastating” impact of dog attacks on postmen and women.
Dr Shaun Davis, of Royal Mail, said: “We are pleased to see such a significant decrease in dog attacks on our staff this past year. However, 33 dog attacks per week on postal workers is still alarmingly high.
Dog attacks remain a major safety hazard and concern for postmen and postwomen across the UK, and the scale of the problem shouldn’t be under-estimated
Dave Joyce, Communication Workers Union
“We are aware that a change in our delivery procedures was the main factor for the reduction in attacks this year. We now need to build on this change, and further reduce the number of attacks on our people.
“So we are asking our customers and our colleagues not to become complacent as there is still much work to do in bringing the figure down even further.”
Dr Davis told The Telegraph discussions were under way to further reduce attacks by finding alternatives to letterboxes.
He said one option included externally mounted post boxes or locker-style post boxes where the customer could give a pin number or a QR code.
He said: “In terms of what we can do to build on reducing dog attacks on postal workers, we are looking at options. There are externally mounted post boxes or there are locker-style post boxes where the customer could give a pin number or a QR code.
“They are quite popular in the US, but you can get them here. They are just being discovered, but are not mainstream yet.
“We wouldn’t mandate it and we don’t endorse products but we might tell customers struggling with a nervous or aggressive dog that they may want to consider this option.”
Royal Mail said it continues to push for changes in the law to reflect the severity of attacks.
Following changes to the Dangerous Dogs Act in England and Wales that came into force in 2014, Royal Mail has carried out more than 25 private prosecutions against dog owners.