Britain counts cost of 50m late letters

By tomorrow morning, 50 million items of post will be stranded in sorting offices as the most serious postal strike for more than 30 years begins to hit home.

London's 13,500 post boxes have been sealed to prevent the backlog building up further, and some people have not received post for 12 consecutive days. Many of the undelivered items will be vital bills and orders, and small businesses in particular are starting to feel the pinch.

The National Federation of Small Businesses said yesterday that the Royal Mail handles a million cheques a day, many of which are destined for small firms. At the independent music label Org Records, in London, its owner, Sean Worrall, said: "This strike could make us go under. Payment from customers is not getting through, but I have to pay bills to pressing plants, to my business landlord, and to a courier company - which is now threatening legal action against me."

Larger businesses are also concerned about the effects of the strike, which started in London and spread to 13 other centres (Bristol, Chelmsford, Colchester, Coventry, Dartford, Maidstone, Milton Keynes, Oxford, Slough, Southend-on-Sea, Stoke-on-Trent, Swindon and Warrington). Bonus Print has seen the 25,000 films a day it normally processes halved, and Tesco, which does 40 per cent of its sales in the six weeks before Christmas, has given the mail-order contract for its book delivery service to another company. At the internet retailer Amazon, a spokesperson said: "We're working with the Royal Mail to minimise the impact on customers, and using Securicor and Parcelforce to help with deliveries."

If the strike continues, consumers will be worried that they will incur fines for late payment of credit card bills. Many firms levy a fine for late payment, but some have said they will waive fines, or "listen to complaints sympathetically". Nationwide said it had suspended fines for late payments, and Barclays Bank said: "We are not in the business of penalising people unduly for situations like this." HSBC said it could not stop automatic computerised fines being made but would refund customers if they appealed. Barclaycard will levy automatic fines, but has told staff to be sympathetic to refund requests. NatWest and the Royal Bank of Scotland made no promises over refunds.

Charities could be among the biggest losers. The next few weeks are the most vital time of year for fundraising, and sales of mail-order gifts and Christmas cards will be badly hit if the strike goes on. Macmillan Cancer Relief said: "Many of our customers are older people who don't feel comfortable ordering over the net or on the phone. Last year, we raised nearly £800,000 from the Christmas sales." The Society for the Protection of Animals Abroad relies on Christmas appeals for 20 per cent of its income and says the strike could cost it £170,000 in lost donations.

Two brighter spots concern the most vulnerable people: hospital patients and benefit recipients. The NHS relies on the post to organise appointments, and send records, test results and samples between hospitals and doctors. But Guy's and St Thomas's hospitals have put in procedures to phone people or contact them through their GP. An NHS spokesman said individual trusts had to ensure essential services are met.

As for benefits, post offices are unaffected by the strike, so pensioners and people can still collect their order books as usual. People expecting Benefits Agency cheques through the post can contact their local office to arrange emergency payments.