More than a dozen Royal Mail postal staff from different delivery offices claim rounds are being missed on a daily basis and parcels are being prioritised over letters as they are stretched beyond capacity.
Postal workers told the BBC some letters sit in postal depots for weeks, while the union representing them describes Royal Mail as "a company in crisis".
Hundreds of people have contacted BBC Your Voice to express frustration over delayed mail resulting in issues including missed hospital appointments.
Royal Mail said: "We want to reassure customers that the vast majority of mail is delivered as planned and understand how frustrating it is when post does not arrive as expected."
Juliet, from Crawley, said she was unimpressed with Royal Mail's letter service recently and late deliveries had very real consequences.
"I have had lots of important NHS letters for appointments arriving after the date," she said.
It was an issue facing Bernard, from Inkberrow, Worcestershire, as well.
"Some first-class letters and appointments take several days to arrive," Bernard said. "It's a complete and expensive mess."
As well as late appointment notices, others have told the BBC about missing school certificates and bank statements.
Now BBC Your Voice has been contacted by postal staff blowing the whistle on what's happening behind the scenes that they think is causing the problems.
"I understand there are delivery offices that clear [all the post] day in and day out, but they are few and far between, and certainly mine isn't one of them", one postman said.
More than 20 postal workers from across the UK have spoken to the BBC Your Voice team. All but one reported delays in their office, and 19 of them told us parcels were still taking priority over all letters. Royal Mail has previously denied this.
"There aren't enough vans to go around… you're going to have to share a van with someone else which means a really bad day where you'll probably end up only doing parcel delivery as that's where the money is for the company, so we're told to prioritise those over the mail," another postie said.
A different postal worker said: "Imagine being an Amazon driver with around 300+ parcels to deliver a day. Now imagine you also have letters to deliver on top of that to around 800+ houses. Every day. It's impossible."
IMAGE SOURCE,JULIET
Image caption,
Juliet says she has had NHS appointment letters arrive late.
Royal Mail is legally required to deliver letters every day, with the exception according to the postal union of 35 delivery offices which are trialling a slower target for mail delivery.
Two current postmen agreed to speak in depth and share pictures of what is going on in their depots.
Tony (not his real name) has worked for Royal Mail for some time, and said things are the worst he's ever seen. "Day in, day out, we're not getting all the mail delivered."
He shared pictures of full racks of mail, as whole rounds are left untouched each day. There is another picture with a tray of mail placed at the front, which he explains was first class mail which is to supposedly to be delivered first. He said the tray has been sitting there for two weeks.
"Parcels are always prioritised, provided they're tracked," he said.
"If they're small parcels and they're first class, then that is supposed to take priority over second class, but the truth of it is if there's a large parcel that's second class we take it because we don't want it in the delivery office, getting in the way the next day."
Over the Christmas period he said, for the first time in his experience, there were two days where no mail was even sorted in his delivery office.
"The trays we were talking about were shoved underneath the frames because it was all hands to sorting out and delivering parcels."
IMAGE SOURCE,SUPPLIED
There are significantly more parcels at Christmas, and plenty of customers agree that parcels should be prioritised over those few weeks. Royal Mail insists that things are now getting back to normal after that unusually busy period, but their staff don't agree.
Most of the Royal Mail staff we spoke to told us that since January overtime has been restricted to next to nothing. Meanwhile some rounds are not being delivered for weeks while posties are on annual leave.
A Royal Mail spokesperson said overtime was reviewed regularly, and a reduction after Christmas was to be expected, but performance was monitored on a daily basis.
The second postman to speak to the BBC, who we are calling Bob, said the reason people were not getting post on time was simple: "There's not enough staff."
"It gets worse after Christmas, because during Christmas they employ a whole team of staff which makes the whole office kind of manageable," he said.
Right now, Bob said: "Every day there's mail left behind, one, maybe two, maybe three rounds which are not covered… The tracked recorded parcels are done every day, because they make a difference to the stats for the office, but anything that's not tracked every day there'll be mail that's not going out."
The regulator Ofcom says it has fined Royal Mail £37m in recent years for its poor letter delivery performance and "will continue to hold the company to account".
The Communication Workers Union agreed for Royal Mail to be bought by a Czech billionaire last April, with the new owners the ED Group promising to "put employees and customers at the heart of everything".
Now, after a period of trying to engage with the new owners, the union is changing its tune.
"I'm not confident that the service is going to improve going forward, it certainly hasn't since Christmas...Royal Mail is a company in crisis," said Craig Anderson from the CWU.
There are still many Royal Mail users happy with the current service. Clive Miller in Oxford contacted BBC Your Voice backing the company: "My first class letters always seem to arrive on time....Maybe I have just been lucky with the post I have sent over the last 10 years."
Royal Mail said its aim was to deliver both letters and parcels on time, but parcels make up a larger proportion of their deliveries and take up much more space than letters. That meant parcels could build up quickly and create physical health risks at depots.
A Royal Mail spokesperson said: "Adverse weather, including storms Goretti, Ingrid and Chandra in January, alongside higher than usual sick absence, has caused some short-term disruption to certain routes.
"Where a delay affects a route, we work to resolve it as quickly as possible by putting in extra support and reviewing performance daily to restore deliveries as quickly as possible."
Postal workers told the BBC some letters sit in postal depots for weeks, while the union representing them describes Royal Mail as "a company in crisis".
Hundreds of people have contacted BBC Your Voice to express frustration over delayed mail resulting in issues including missed hospital appointments.
Royal Mail said: "We want to reassure customers that the vast majority of mail is delivered as planned and understand how frustrating it is when post does not arrive as expected."
Juliet, from Crawley, said she was unimpressed with Royal Mail's letter service recently and late deliveries had very real consequences.
"I have had lots of important NHS letters for appointments arriving after the date," she said.
It was an issue facing Bernard, from Inkberrow, Worcestershire, as well.
"Some first-class letters and appointments take several days to arrive," Bernard said. "It's a complete and expensive mess."
As well as late appointment notices, others have told the BBC about missing school certificates and bank statements.
Now BBC Your Voice has been contacted by postal staff blowing the whistle on what's happening behind the scenes that they think is causing the problems.
"I understand there are delivery offices that clear [all the post] day in and day out, but they are few and far between, and certainly mine isn't one of them", one postman said.
More than 20 postal workers from across the UK have spoken to the BBC Your Voice team. All but one reported delays in their office, and 19 of them told us parcels were still taking priority over all letters. Royal Mail has previously denied this.
"There aren't enough vans to go around… you're going to have to share a van with someone else which means a really bad day where you'll probably end up only doing parcel delivery as that's where the money is for the company, so we're told to prioritise those over the mail," another postie said.
A different postal worker said: "Imagine being an Amazon driver with around 300+ parcels to deliver a day. Now imagine you also have letters to deliver on top of that to around 800+ houses. Every day. It's impossible."
Image caption,
Juliet says she has had NHS appointment letters arrive late.
Royal Mail is legally required to deliver letters every day, with the exception according to the postal union of 35 delivery offices which are trialling a slower target for mail delivery.
Two current postmen agreed to speak in depth and share pictures of what is going on in their depots.
Tony (not his real name) has worked for Royal Mail for some time, and said things are the worst he's ever seen. "Day in, day out, we're not getting all the mail delivered."
He shared pictures of full racks of mail, as whole rounds are left untouched each day. There is another picture with a tray of mail placed at the front, which he explains was first class mail which is to supposedly to be delivered first. He said the tray has been sitting there for two weeks.
"Parcels are always prioritised, provided they're tracked," he said.
"If they're small parcels and they're first class, then that is supposed to take priority over second class, but the truth of it is if there's a large parcel that's second class we take it because we don't want it in the delivery office, getting in the way the next day."
Over the Christmas period he said, for the first time in his experience, there were two days where no mail was even sorted in his delivery office.
"The trays we were talking about were shoved underneath the frames because it was all hands to sorting out and delivering parcels."
There are significantly more parcels at Christmas, and plenty of customers agree that parcels should be prioritised over those few weeks. Royal Mail insists that things are now getting back to normal after that unusually busy period, but their staff don't agree.
Most of the Royal Mail staff we spoke to told us that since January overtime has been restricted to next to nothing. Meanwhile some rounds are not being delivered for weeks while posties are on annual leave.
A Royal Mail spokesperson said overtime was reviewed regularly, and a reduction after Christmas was to be expected, but performance was monitored on a daily basis.
The second postman to speak to the BBC, who we are calling Bob, said the reason people were not getting post on time was simple: "There's not enough staff."
"It gets worse after Christmas, because during Christmas they employ a whole team of staff which makes the whole office kind of manageable," he said.
Right now, Bob said: "Every day there's mail left behind, one, maybe two, maybe three rounds which are not covered… The tracked recorded parcels are done every day, because they make a difference to the stats for the office, but anything that's not tracked every day there'll be mail that's not going out."
The regulator Ofcom says it has fined Royal Mail £37m in recent years for its poor letter delivery performance and "will continue to hold the company to account".
The Communication Workers Union agreed for Royal Mail to be bought by a Czech billionaire last April, with the new owners the ED Group promising to "put employees and customers at the heart of everything".
Now, after a period of trying to engage with the new owners, the union is changing its tune.
"I'm not confident that the service is going to improve going forward, it certainly hasn't since Christmas...Royal Mail is a company in crisis," said Craig Anderson from the CWU.
There are still many Royal Mail users happy with the current service. Clive Miller in Oxford contacted BBC Your Voice backing the company: "My first class letters always seem to arrive on time....Maybe I have just been lucky with the post I have sent over the last 10 years."
Royal Mail said its aim was to deliver both letters and parcels on time, but parcels make up a larger proportion of their deliveries and take up much more space than letters. That meant parcels could build up quickly and create physical health risks at depots.
A Royal Mail spokesperson said: "Adverse weather, including storms Goretti, Ingrid and Chandra in January, alongside higher than usual sick absence, has caused some short-term disruption to certain routes.
"Where a delay affects a route, we work to resolve it as quickly as possible by putting in extra support and reviewing performance daily to restore deliveries as quickly as possible."
