It's not because they think that the OP is dodgy... They just don't want her because she's costing them money.

The HSBC business account thing is because they got in trouble for not preventing money laundering with the US and they're being overly cautious. There was some paperwork everyone had to fill in regarding their accounts and there have been a bunch of clerical/admin errors in their system regarding that form.

Plenty of businesses deposit cash regularly. They just prefer you to pay a monthly fee for this.

my accountant told me opposite..it is better to have just one! now, i am wondering if they (bank) want to sell you it....i m guessing!
maybe you could have some benefits, but you will be charged to have it?....
bankers...they do business, i do not trust sooo much! (am i wrong?) they do not care your interests...accountant should care about your interest..
Anyway i will ask to my accountant...what are interested to open a business account...
To me is more ease to have just one to handle better....even when i worked as escort and i worked in a civy job all money went in the same...without issues!

i am with barclays and never had this kind of issue, but i am paying tax and bank can see that because i payed tax from my bank account!

to get attention from bank... i think you should transfer a lot of money.... but really a lot constantly...
i do not think that ?3000/?4000 they notice....it is not sooo much for them (my opinion but i do not work in a bank)

the best thing it is calling to them and ask for an explanation...
Anyway there are a lot of banks in uk, so you have a lot of choice!

It will be several hundred most weeks.  Should I mention to Nationwide?

I have the same issue now but with lloyds and Halifax.I went to the bank and appeal from the decision.Now they want from me my business account statements for last 6 MK this,my pay pal statement for last 6 month,marriage certificate and if I have any document that I pay taxes.

I have the same issue now but with lloyds and Halifax.I went to the bank and appeal from the decision.Now they want from me my business account statements for last 6 MK this,my pay pal statement for last 6 month,marriage certificate and if I have any document that I pay taxes. I think I will just close this accounts and leave it as it is.I opened another with Barclays and have my business account with bat west.Basiccaly they've told me it's because of a bit more money I put to my account in cash last 3 months.

The money laundering aspect has already been touched on, however, your problem *may* possibly stem from your customers (not you) depositing cash in to your account (if this scenario applies to you). Banks are supposed to know their customers and I've seen first hand where a professional business woman had a number of accounts closed due to chunky cash deposits being paid into some of her accounts (which were a mixture of business/personal). She was queried about it by the bank, who were not satisfied with her explanation and who after giving notice, subsequently closed all of her accounts at the same time. The reasons cited where to do with money laundering concerns and the cash deposits being made into her accounts by unknown persons.

For clarification;

1.  I believe the deposits related to different amounts paid in from a few hundred up to a maximum of ?5,000.00. (I think ?5K as a cash deposit is a red flag anyway).

2. Due to being unaware that someone was paying money into her account (the client failed to notify her in advance or put a reference on the cash deposit). She was unable to confirm with any certainty who made the deposit.

3. If you have a personal account and are treating it as a business account (and the bank are unaware that you are running a business/self employed). All the transactions into the account may look suspicious to the bank if they only expect to see wages/benefits paid into it.