Not sure who supplies your business gas? It's more common than you'd think, especially if you've just moved in or a landlord used to handle it. You can find out for free in a few minutes. Here are three ways to do it, and why it's worth knowing.

Check your latest gas bill

This is the quickest way. Your supplier's name and contact details are on every bill, and so is your MPRN, which is your gas supply number.

Use Find My Supplier

If you're reading this guide, chances are you don't have a bill to hand. Sometimes people don't get paper bills or they're delivered to a different address. Don't worry - even if you don't have a bill, you can still find out. Use the free Find My Supplier service at findmysupplier.energy. It's run by Xoserve, the company that keeps the national gas records. Enter your postcode and pick your address, and it'll show your gas supplier, your MPRN and your gas network company.

Call the helpline

If neither of those options suit you, you can call the Meter Number Helpline on 0870 608 1524. Give them your address and they'll tell you your MPRN and who supplies your gas. Calls aren't free, so you might want to check the cost with your phone provider first in case you're kept on hold.

Why do I need my MPRN?

That MPRN we mentioned above stands for Meter Point Reference Number. It's a number of between six and ten digits that identifies your gas supply. It stays the same when you change supplier, and you'll need it when you compare prices or switch.

If you've just moved in

When you move into new premises, there will already be a gas supplier for the property. Until you agree your own contract, you'll usually be on a default rate with that supplier, and these tend to be expensive. So it's a good idea to sort it quickly.

• Find out who your gas supplier is using the steps above.

• Let them know when you moved in.

• Provide your supplier with a meter reading from the day you moved in.

• Ask about your current rate and options.

• Compare deals and switch to a contract that suits your business.

Supplier or network?

They're two different companies. Your supplier sells you gas and bills you. Your gas network, also called your gas transporter, owns the pipes and keeps them safe. There are four main network companies in Britain: Cadent, SGN, Northern Gas Networks and Wales and West Utilities.

If you ever smell gas, call the National Gas Emergency Service on 0800 111 999. It's free, and they'll help regardless of who your supplier is.

How do I find my company's electricity supplier?

Gas and electricity are separate, and you can have a different supplier for each. To find your electricity supplier, check your bill. If you don't have one, contact your local network operator and give them your postcode.

If the landlord or previous tenant has unpaid energy debt

Ask your landlord or agent for the last gas bill or the supplier's name. You're not responsible for the previous occupant's debt, even if the supplier chases you. Tell them you're the new occupier, and give your move-in date and a meter reading and they should leave you alone.

Why it's worth knowing your gas supplier and MPRN

Without your MPRN, you can't compare deals. And without your supplier's name, you can't report a billing problem. It might not feel like a priority but a few minutes now could save you money and hassle down the line.