Companies that may rent a business premises to conduct their work such as, a workshop, warehouse or a suite of offices would be their trading address.
Your trading address is used for all your day-to-day business correspondences, such as paperwork from your suppliers, customers, deliveries, banking, and finance.
You can receive mail and parcels to your trading address, meaning it is often used as the business's returns address to protect the businesses' residential address. Unless your company is renting an office, the company trading address (aka business address) will be your home address.
When you open a company bank account it is at this address that your bank will send the account details, chequebook, debit card, and other bank correspondence.
Your trading address should be prominent on any invoices you issue.
It is at this address you want your clients sending purchase orders, payment confirmations, contracts for services etc.