To think a 1st Class letter should reach it's destination?

I think you get these 'little Hitlers' sometimes in post offices. We used to have one. Thankfully she's gone now. Ignore. There is always an outside chance that any letter could go missing but the odds are strongly for it being fine.

Perhaps she has a subsidiary business reselling the contents of letters that havn't had £12.80 paid on them?

Thanks for that Elegran basically she seemed to be saying that unless i paid the £12.80 my letters would go missing !

I invariably pay normal 1 St or 2 nd class post despite being told of the more expensive options. I would do the same for a passport application.

gillybob She should read the terms and conditions :-

"1st Class mail offers a fast, cost-effective, UK-wide delivery service for letters weighing up to 750g that aims to deliver your item the next working day, including Saturdays.

At a Glance

Aims to deliver the next working day including Saturdays
Fast UK-wide delivery for letters up to 750g
Up to £20 compensation cover for loss or damage "

I does AIM to deliver the next working day, though it may not always succeed, and £20 is not much, but it is not quite "if they were lost or went missing I would not be compensated"

i think she was hoping to get the £12.80. After all, even sending it "Royal Mail signed for" only promises :-

" Confirm online or via your mobile when your item has been delivered
Aim to deliver next working day, including Saturdays
Proof of delivery including a signature from the receiver
Prices start at £1.73 for letters up to 100g
Compensation cover up to £50. Excludes jewellery and money (coins, cash, postal orders, bonds and coupons or vouchers exchanges for money, goods or services, which includes tickets)."