The phrase 'wheelchair accessible' covers a lot of ground, and not all of it will fit a powered chair with a user in it. Booking one is less about finding a firm that says yes and more about asking the questions that turn a yes into a car that works.

Which vehicles count, and which do not

In many towns, some or all of the hackney carriage fleet is required by the council to be wheelchair accessible, which is why purpose-built taxis with a ramp and a rear or side entry are common on ranks. London's black cabs all carry a ramp. Private hire fleets vary far more: some run converted vans or people carriers with a tail lift, some have none at all.

The catch is that 'accessible' can mean a folding manual chair goes in the boot while the passenger transfers to a seat, or it can mean the passenger stays in the chair, secured, for the whole journey. If you need the second, say so in those words when you book.

The questions that avoid a wasted booking

Give the office the chair's make and whether it is manual or powered, its approximate length and width, and the combined weight if it is a heavy powered model. Ask what the vehicle's ramp or lift is rated to carry and what internal height it offers, because a tall user in a raised chair can be turned away at the kerb by a roof that is a few centimetres too low. Ask whether the driver has been trained on the restraint system, and whether a carer travels free, which is the policy at many firms.

If the office cannot answer these, they are guessing, and you will find out whether the guess was right when the car arrives.

What the law says about refusals and charges

Under the Equality Act, the driver of a designated wheelchair-accessible taxi or private hire vehicle must carry a passenger in a wheelchair, give reasonable assistance, and must not charge extra for doing so. Councils keep lists of designated vehicles. A similar duty covers assistance dogs across the whole trade, not just accessible vehicles. If a firm quotes a higher fare because of the chair, that is a red flag as well as a breach.

Waiting time is different. If loading takes a few minutes, a reasonable firm builds that into the fare or simply absorbs it. A meter will keep running in a hackney carriage, so ask how the office handles it.

Booking ahead and building a relationship

Accessible vehicles are usually a small part of any fleet, so a same-day booking at school-run time is a gamble. Book hospital appointments and regular trips as far ahead as you can, and if you find a firm and a driver who get it right, ask the office to put a note on your account so the same vehicle is sent each time. Most will, gladly.

Picture a weekly dialysis run at 7am. The firm that handles it well will have the vehicle allocated the night before, the driver will know the ramp angle at your front door, and the return trip will be booked in the same call. That is the standard to hold every firm to.

Some of the 2,635 taxi companies listed here state their accessible vehicles openly, and others will tell you within a minute of ringing. You can browse the firms serving your area and look for the ones that mention wheelchair-accessible vehicles, or set out the chair and the journey and let firms that can genuinely do it reply.

Keep the chair's measurements in your phone. Reading them out is the fastest way to get a straight answer from any office.