Businesses signing up for XLN Telecom's line rental, unlimited calls and broadband package are currently entitled to receive a £20 Marks & Spencer voucher.
The gift certificate offer is available for a limited time only on the business broadband package, which is priced at just £11.99 per month for the first nine months.
XLN says it is charging small companies only for line rental during the introductory period of their contract.
After nine months, the broadband deal reverts to the standard price of £34.98 per month.
However, XLN claims this is still cheaper than TalkTalk and BT's equivalent business broadband deals.
With the Business Max deal, companies receive the fastest speeds possible on XLN's network and an unlimited usage allowance.
They are also able to take advantage of unlimited calls to 01, 02 and 03 numbers and a free router, adding to the savings possible with the deal.
XLN Secure is also available to subscribers, enabling them to keep their connections secure.
The firm - which currently provides telecom services to more than 130,000 businesses - urges firms to "get peace of mind with the ultimate business bundle".
Companies looking to spend less on their broadband deal after nine months have the option of signing up for XLN's Business Basic package.
This offers high-speed broadband, a 20GB usage allowance, 3.9p/min Local/National calls and a free router for £7.99 per month, with line rental costing an additional £11.99 per month.
This cost of the broadband deal is £19.98 per month plus any call charges.