Foreign call company SIM4Travel, which provides low cost prepay roaming SIMs, has struck a deal with lastminute.com.
Its SIM cards will be available to travellers buying holidays from the web travel agent.
SIM4Travel marketing director Suk Grewal said: "The industries are similar. Travel agencies prefer all travel accessories to be sold together so they receive maximum commission and mobile shops want to sell all mobile related goods so they receive theirs.
"We don’t see our product as being exclusive to one field so we’re hoping to expand in both fields in the future."
Customers can currently receive £10 airtime for £5 when purchased via the site.