You should check the register at Companies House, using the free Webcheck service.
How do you check if a limited liability partnership is carrying on business in the UK?
You must be satisfied that the LLP is carrying on business in the UK. The business can be non-profit making.
Even if you have direct personal knowledge of the LLP, you should check the Companies House register to see if:
the LLP is in liquidation, dormant, or about to be struck off
the LLP’s accounts and annual return are overdue
An LLP may still be carrying on business if it is in liquidation, dormant or late in filing documents, but you should make extra checks to satisfy yourself that this is the case.
For any LLP, you should consider looking at:
the LLP’s website
relevant trade, telephone directories or reputable websites
the latest accounts filed at Companies House
If you are still not sure if the LLP is carrying on business in the UK, you should ask for written confirmation of its business activities from the LLP’s directors.