Across-the-board increases are easy to communicate internally but blunt in practice. They hit customers with healthy margins just as hard as those already priced too low.
A better starting point is to segment the increase: a larger adjustment where the price deviates most from what you normally charge, a smaller one where the relationship is price-sensitive and the margin already reasonable.
Simulate the outcome before you go out. With historical data you can estimate how much volume would have to disappear for the increase to be unprofitable — and that number usually calms the discussion.