Can I make upgrade to the higher version? How much is cost this upgrade?

Yes, its possible to make upgrade from lower version to the higher versions of the same editions (for example from the Booking Calendar Personal single site usage version to the Booking Calendar Business Small single site usage version).
But its does not possible to make upgrade from the single site usage version to the "developer" or multi site usage versions or from the "developer" to the multi site usage versions.
The cost of upgrade from the lower to higher versions, usually higher than difference in cost between 2 versions.
The cost of upgrade from the lower to higher versions of single site usage versions higher on $20 than difference in cost between 2 versions.
The cost of upgrade from the lower to higher versions of "developer" edition versions higher on $30 than difference in cost between 2 versions.
The cost of upgrade from the lower to higher versions of multi site usage versions higher on $50 than difference in cost between 2 versions.

I need new feature, can you make customization for me ?

Unfortunately we can not make personal customization or custom development on customer demand. But we can add features, that you need to our TODO list for implementing them in a future updates. You can add your request of specific feature at this page.
Please note, we can not specify some approximate time for implementation of the specific feature but we will make the best to implement specific feature ASAP.

What version do I need ?

You can check overview of different Booking Calendar versions.
You can also check all available features for different versions of Booking Calendar.
Also you can test live demo of specific versions (both client and admin sides) to be sure in functionality and do not have misunderstanding.

What the difference between single site usage, developer and multi site usage versions ?

Each specific version of Booking Calendar can be single site usage version, developer or multi site usage version.
Single site usage version, possible to install and activate only at 1 specific website.
Developer edition version, possible to install and activate at 2 different websites. Its can be test (developer) server and live website.
Multi site usage version, possible to install and activate maximum on 5 different websites.

How long I can get free updates ?

You can request free updates your version of Booking Calendar (if such updates ready) during 6 months after purchase of plugin. You can request new update of Booking Calendar on this page.
If you will need to extend period (of support and getting free updates) to the next 6 months, it will cost 50% from the original cost.

Is it one time cost ?

It's one time cost. You can use your purchased version of Booking Calendar as long as you need on your website.

Also, you can request free updates your version of Booking Calendar (if such updates ready) during 6 months after purchase of plugin. You can request new update of Booking Calendar on this page.
If you will need to extend period (of support and getting free updates) to the next 6 months, it will cost 50% from the original cost.

Overview of Booking Calendar versions

Booking Calendar "Free" - this version is free, you can download it from WordPress directory.
It's very easy in use and powerful version for the creating reservation of one resource.
At this version is possible to make reservation for the one resource, like a room or car, or some service... etc. You can insert into the post or page the standard booking form with fixed number of fields and availability calendar, where visitor can select single or multiple days. Administrator and visitor can receive the standard email notifications about different actions, like a "new booking", "approve/decline/... of booking", etc... Administrator can make the booking at admin panel at the "Add new booking" menu page and configure the different settings of the booking form and availability calendar at the general booking settings menu page.

Booking Calendar Personal - it's paid version, where is possible to have booking availability calendar for the each of multiple booking resources (like a room, cars or any services, etc…). You can add new and configure exist fields in the booking form. Also you can configure the email templates for the different booking actions. You can able to edit the exist bookings, add comments to the bookings, print and export bookings to the CSV format, etc… Please check at the feature list and live demo of this version, full list of features of this version.

Booking Calendar Business Small - it's paid version, where is possible all actions from previous versions, plus you can receive the bookings for the specific time of date, set the cost of booking resource and integrate the online payment form of supported payment systems. Your visitors can make the rage days selection using the one mouse click in calendar, or setting minimum or sets of fixed number of days selection using 2 mouse clicks (check in and checkout dates), all middle dates will be selected automatically. Also here is possible to use the same date as check in/out date for the different bookings by activating the fixed time at the settings page.
Please note, if you will use the fixed time slot list selection (and not the time entering using the text fields) in the booking form, the timeslot list will be the same for the any date of week, in other words the fixed time slot list is not depend from the week of day. Also if some visitor will reserve the specific time slot at selected date at specific booking resource (calendar), this timeslot become unavailable for the other visitors at this selected date in this booking resource.
And much more... Please check at the feature list and live demo of this version, full list of features of this version.

Booking Calendar Business Medium - it's paid version, where is possible all actions from previous versions, plus you will have more advanced cost and availability management of the bookings. At this version is possible to set the rates, which will depend from the season filters, plus you can set the more advanced cost for the booking, where cost is depend from the number of selected dates. Also you can set additional cost for the option selection at selectboxes or checkboxes at your booking form. this additional cost can be fixed sum or percent from the final cost of booking. You can even activate and configure for the resources the deposit payment feature, what is mean that visitor will pay at the payment form, the part of the final cost of the booking. This version is also support settings availability per each booking resource, which is depend from the season filters. Also you can able to configure the several customization of booking form fields, it's mean that different resources can have different form fields. You can send the payment requests to visitors for the specific booking by email. And much more.... Please check at the feature list and live demo of this version, full list of features of this version.

Booking Calendar Business Large - it's paid version, where is possible all actions from previous versions, plus you can make the several reservations per the same FULL date (not a time slot) for the same booking resource (availability calendar). At this version is possible to set the capacity of the booking resource, it's mean that your visitors can make the several reservations per the same date, in other words, the date(s) in calendar will be available until lumber of reservations per these full dates is less than capacity of the booking resource. Please note, if you will use the timeslot selection for the booking resource with capacity higher than one, so then this timeslot will be simply record as a data into DB according this booking, but will not impact to the time availability. Also at this version you will be able to search the available booking resources in your pages or posts for the specific check in/out dates and specific number of visitors. This version is also support the coupon codes for getting discounts of bookings. And much more.... Please check at the feature list and live demo of this version, full list of features of this version.

Booking Calendar MultiUser - it's paid version, where is possible all actions from previous versions, plus each registered WordPress user of your site can have independent, individual, own booking admin panel. It's mean that each regular registered WordPress user can see only OWN booking resources and bookings and can configure the own booking form fields and email templates, own payment form integration data and costs of booking resources as some other settings... In this version is exist also the "super booking admin users", which can see and manage the bookings and booking resources from the all users and manage the status of other bookings users. And much more.... Please check at the feature list and live demo of this version, full list of features of this version.