For example, Geico allows customers to delay automatic payment of invoices by up to nine days through the company's mobile app. The agent you're working with may have some discretion over how much leeway they give you, especially if you have a credible reason why you won't be able to make the payment. If you need to postpone a payment from Geico or a payment from another insurance company, contact them directly to ask if this is possible. The sooner you do it during the month, the more likely they are to be able to help.
Don't let your policy expire or your payment be delayed. The insurance company may not automatically accept a late payment. If you pay in advance, then yes, you will receive a refund for the unused portion of your payments if you cancel your Geico policy. You can contact Geico to see how much you will receive and when you will receive it.
You may be able to increase your car insurance deductible to a larger amount (as long as you can pay that payment out of pocket), which could help lower your premium.