Other business surveys and official data have suggested the economy started 2024 on a stronger footing after it went into a recession in the second half of 2023.
The PMI will be studied by the Bank of England, which is watching for signs that underlying inflation pressures are abating sufficiently for it to cut interest rates.
The survey’s employment index showed staffing levels shrank for the 18th month in a row but at the slowest pace since May last year.
Input costs gathered a bit more speed, rising at the fastest pace in a year, and companies increased the prices they charge by the most since last May.
Disruption to shipping in the Red Sea lengthened delivery times for supplies.