busy periods. They can be internal or external. Internal locums have their substantive post at the hospital and are working additional hours from the NHS sta bank. External locums are working away from their base hospital (or do not have one), often on behalf of private locum agencies. There are many locum agencies that you can register with; they are often advertised in BMJ Careers. To reduce spending on locums, two key measures have been introduced. The rst of these, caps on total hourly rates, seems to have had little success. The capped rates are much lower than those previously oered such that trusts that enforce them have a much harder time lling rota gaps, resulting in unlled slots and increased strain on other doctors. An ‘exceptional circumstances’ clause allowing the cap to be broken has been widely used by many trusts, with several continuing to pay rates similar to or above those oered before the introduction of the cap. Rates of pay will vary and can still be negotiated, but an F can expect pre- tax rates of £20– 30/ h, and F2s £25– 35/ h. The second new measure is a clause in the 206 junior doctors’ contract specifying that those doctors planning to take locum work must initially oer their services for the proposed shift time to their employing trust sta bank. The trust must respond in a timely manner indicating if they require the doctor’s services. The doctor is under no ob­ligation to take any extra shifts on, but would not be able to take an agency locum if the trust had oered sta bank work at an appropriate level (not a lower grade). Importantly, you should discuss locum shifts with your super­visor and include them in your work schedule to ensure contractual limits on individual and average weekly working hours (48h or 56h depending on if you’ve opted out of the EWTD) are not exceeded.