Two men entered the Café On The Cobbles in Alford Market Place and asked for different denominations of change, leaving with an extra £120.
A police spokesman said: “We would like to speak with these men in connection with this theft which was carried out on October 11.
“One of the males was in his late 20s, around 5ft 8, of a stocky build and wearing a baseball cap backwards.
“The other male was mid to late 20s, around 5ft 8, and was wearing a puffer style jacket.
“If you recognise these men or can assist with our investigation, please contact us.”
Get in touch with Lincolnshire Police in one of the following ways:
• By calling 101 quoting the reference 317 of October 11.
• By e-mailing [email protected] - remember to include the reference 317 of October 11 in the subject box.
• By contacting the independent charity Crimestoppers, anonymously, on 0800 555 111 or online at crimestoppers-uk.org.