The maximum loan-to-value (LTV) ratio for a commercial buy-to-let mortgage can vary between lenders, the type of property, and the financial strength of the borrower. However, it is typically lower than for residential mortgages due to the perceived higher risk associated with commercial properties. In general, you might expect a maximum LTV of around 70% to 75%, although in some cases, it might be as low as 60%. This means you would need a deposit of between 25% to 40% of the property's value. It's worth noting that more favourable terms may be offered to those with a lower LTV, as the risk to the lender is reduced.