Lisa
Here's a tune to cheer you up.
VERSE: It's a well known fact that the banks will give you an umbrella when the weather is fine, and demand it back when the rain comes.
CHORUS: Oh what high street bankers (rhyming slang) they are.
It's a very popular song, and bad credit is an unfortunate bind at best. But when, finally, the fat lady has sang, there is no option, as a business person, but to fix your credit rating.
Start by following Fox's suggestions. The two most widely used credit reference agencies are: Experian and Equifax. Your credit file from either(get both) will cost you £2 each.
Don't be afraid to ask the people you owe(if you still do) to reduce the amount outstanding in return for a quick settlement. Be sure to get a letter from them saying you have totally settled your debt, then send a copy to the credit reference agencies.
To start to rebuild your rating get a credit card as soon as you are able. Someone like CapitalOne will consider you when others have refused. Put only those spends which you are able to pay off each month, so as not to attract any interest. The point here is to create a history of creditworhiness.
The challenge I would set myself is to have a rating so safe, that I would have the pick of the banking institutions and their facilities at most favourable rates. Of course they speak a different language to the rest of human kind. As a business person, however, it's at least worth brushing up to conversational level.
Best
Freddie