The Communication Workers Union has organised two UK-wide strikes on Thursday and Friday in a row over pay, conditions and modernisation plans. Here people in businesses across the UK share their opinions and tell us how it will affect them.
GRAHAM RUBIN, MAIL ORDER BUSINESS, LIVERPOOL
I have a mail order company with a turnover of £30 million and I employ over 200 staff. I have just stopped a contract with Royal Mail for over £1 million pounds and I will not return to them. I believe it is time to allow their competitors to take over the "final mile" and deliver the post to the doorstep.
If the strike goes ahead I will have to lay off employees at potentially the busiest time of the year. I have been in business for 30 years selling clothes and household goods mainly targeted at older people.
Almost every year the postal workers hold us to ransom. We typically deal with some 3000 parcels and letters a day and we are going into our peak time now which would normally see a a rise to 5000. Many customers have been put off by the postal strikes and it's our business has been dramatically affected.
We are constantly trying to reassure and find solutions. We encourage customers to use the phone where possible. We have now stopped using Royal Mail altogether and only use private courier firms - something we include prominently in our advertising.
The courier services have been good and they even offer a full tracking and tracing service.
I now think that it is time to see some proper competition in the market. Royal Mail have a monopoly on the final mile. I just don't understand why they should put our workers livelihoods at stake.
ANDREW TITCOMBE, RECORD MAIL ORDER BUSINESS, CUMBRIA
After 30 years in the mail order trade selling collectible music, this strike has made me seriously consider running a real shop again.
For the past ten years I have been selling successfully on Ebay and Amazon. Some orders are delivered next day while some international ones are taking up to four weeks. Many sellers are concerned about the strike because on Ebay feedback is reflected in the time you take to deliver your orders. At the moment I am a top rated seller but if there are delays you get marked down.
Over the last three weeks I have seen a downturn in business of about 30 to 40% as people begin to realise that the strike could delay their orders. Normally you would expect to see an increase in sales as we approach Christmas.
I think that Royal Mail has damaged the market and if in the future it goes then the business I run will be severely affected. It costs around 90 pence for next day delivery for a CD or seven inch single. No one else can compete on those prices and this will definitely affect the cheaper end of mail order businesses.
I have recently had the offer of running a local shop. Under normal circumstances I wouldn't take it but perhaps this is the writing on the wall?
MICHAEL BYRON-KRAUS, MAIL ORDER BUSINESS, CLEVELAND
My wife and I run a small business from home and we have a daily collection from Royal Mail. We are 100% behind the CWU and would urge this supposedly Labour government to realise their priorities should be with the workers and not the corporations.
My wife and I sell lingerie on the internet. We send out 100 parcels a day and obviously we will miss out on our daily collections during the strike. After the recent localised strikes some of our post has taken longer to get through so we have been doing more special deliveries.
We have a good relationship with our postmen and they explained why they were taking industrial action. From their point of view it's never been anything to do with pay. It's about the unagreed changes to their working patterns and duties. We feel strongly that the postal workers aren't getting the support they deserve.
We wrote to our customers and explained there would be delays but they would still get their orders. The vast majority of them have been very understanding and supportive.
I don't think the strike will have a major effect
Although our business is down on last year, it's not as bad as we thought and I don't think the strike will have a major effect. I am more concerned about what would happen if Royal Mail is privatised. The Conservatives have hinted they would do this if they got into power. If it happened it would really affect us because we just can't afford couriers' prices.
PETER QUINN, UNITED PRESS
We are receiving post that is up to six weeks late. This week I have received mail dated from August! I am the managing director of a publishing company and like most businesses ours is time sensitive. I think the postal workers are destroying their business and bringing others down with them.
Localised strikes have directly affected our work. Proofs have been late, making books delayed, invoices and payments haven't arrived and everything is going slower. We pay Royal Mail business rates for a reliable postal service but from my personal experience they don't even do the work they are paid for.
We have already been adversely hit by the recession. We have had to make 20% of our workforce redundant. What makes me furious is that postal workers don't seem to realise this. There are two and a half million people out of work and many businesses are suffering yet they don't seem to have an inkling of what it's really like out there.
Once we only used Royal Mail but now we are using some of their competitors as well. The competitors are taking work from Royal Mail because of their refusal to modernise.
As I run a small business I must take immediate action to ensure my invoices are delivered to my customers. The unions and the Royal Mail have forced me to invest in some new software allowing me to e-mail my invoices, statements and remittance advices. I cannot see any circumstances were my business would return to using slow mail.
Steve Orr, Rugby
After recently being made redundant, I have set myself up as a freelance trainer and the majority of my customers pay me by cheque. Most of these are sent via Royal Mail after the training has been completed. The strikes will delay the delivery of my payments unless I can persuade my customers to pay me on the day or via BACS transfer, which most of them do not wish to do. My only alternative will be to make a second visit to collect the payment cheque which costs me more in time and petrol.
John Valentine, Guildford
We own an online fancy dress business. Halloween is coming up and this is our busiest week of the year for orders. Our sales are down by around 40% compared to this time last year because people are worried they will not receive their items on time. We do not know if we will survive.
Chrys Connor, Doncaster
I run a small online business selling my own motor sport artwork and prints. This strike and the local strikes that have happened over the past couple of weeks have seriously affected my business. I have had irate customers complaining to me that their package hasn't arrived, even though its out of my control. I have also seen a dip in sales this week as people are delaying their purchases not knowing when or even if their order will arrive.
I have a small business which like many small business has been hit hard by the recession. Cash flow is vital therefore any delays in receiving cheques and orders will further damage recovery for a lot of small businesses.
Jonathan Woolhouse, Sheffield
I've just moved my e-commerce store deliveries from Royal Mail to couriers and I don't think I'll be going back either.
Paul M, Durham
I run a small business serving lawyers which is dependent on the post. Two weeks ago, I joined the Document Exchange which most lawyers use. Now 80% of my mail is lost to Royal Mail.
Small Businessman, Buckinghamshire