So I have just had a look on Rent a Room and found this -
The Rent-a-Room Scheme allows owner occupiers and tenants to receive tax-free rental income if you provide furnished accommodation in your only or main home.
The annual Rent-a-Room limit is £4,250. This reduces to £2,125 if someone else receives income from letting accommodation in the same property, such as a joint owner. The limit is the same even if you let accommodation for less than 12 months.
When you can use the Rent-a-Room Scheme
You can use the scheme if:
you let a furnished room to a lodger
your letting activity amounts to a trade, for example, if you run a guest house or bed and breakfast business, or provide services, such as meals and cleaning
When you can’t use the Rent-a-Room Scheme
You can’t use the scheme if the accommodation is:
not part of your main home when you let it
not furnished
used as an office or for any business - you can use the scheme if your lodger works in your home in the evening or at weekends or is a student who is provided with study facilities
in your UK home and is let while you live abroad
the whole of your home, rather than a part of it
Rent-a-Room Scheme
If your gross receipts from letting are not more than the Rent-a-Room limit of £4,250 (or £2,125), you don’t pay tax on your profit. If they are more than the limit, you may still be able to benefit under the Rent-a-Room Scheme.
Your gross receipts include:
rental income (before expenses)
any amounts you receive for meals, goods and services, such as cleaning or laundry
any ‘balancing charges’
You usually count your gross receipts for a tax year - that is, from 6 April one year to 5 April the next.
If your letting activity amounts to a trade, you count your gross receipts for your basis period. Helpsheet 222 How to calculate your taxable profits provides more information.
If your gross receipts are less than the Rent-a-Room limit
If your gross receipts are less than £4,250 (or £2,125), you are automatically exempt from tax on that income.
If you have made a loss, however, it may be better for you to pay tax in the normal way - that is, on your receipts less expenses. You will need to tell HMRC that you want to do this within the time limit.
So, Do I let the tax office know as my DD's keep is way below the requirements! 