Bankers and borrowers are bracing themselves for a difficult year selling eurobonds now that the days of easy money are coming to an end.

January's often the busiest month of the year for new bond sales, but as credit markets lose their biggest backer and political threats loom—including Brexit, Italian fiscal angst, and trade woes—companies must wise up to 2019's primary-market challenges. In vogue: opportunism, front-loaded issuance, and higher borrowing costs.

“The year as a whole will be window-driven, but many will try to access the market in January,” says Duane Elgey, a debt syndicate director at Societe Generale SA. “Once it is accepted that spreads are not returning to early-2018 levels, there will be a number of deals coming back to market.”