I'm looking into building an app that does custom tax calculation at checkout. It will communicate with another system which does the calculation. In other words, I'm trying to build something that works similar to the likes of Avatax etc but this is a unique project for one store.
How do those apps work? I have not found any APIs, documentation or forum comments to really help so I'm hoping someone might point me in the general direction.
As I see it, we need to modify the checkout object after the customer enters their shipping address and proceeds to payment. This appears to be the point at which a checkout object is created.
I can listen for checkout/create and checkout/update web hooks to know when we need to do the calculation. The two APIs that allow access to the checkout are the Sales Channel API and Storefront API.
Sales Channel API returns the tax lines in the checkout object but the documentation indicates that they're read-only. This doesn't feel like the correct API anyway. I'm not trying to provide a sales channel for third party stores.
Storefront API sounds more appropriate. I can use GraphQL but I don't see a mutation capable of updating tax lines.
I'd appreciate anyone sharing the general idea of how these tax calculator apps work. Maybe I'm missing the obvious or maybe they use some secret unpublished API.
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Thanks but my question was about tax, not shipping rates.
I think some further research has answered my question. There is or was an API called the Tax Services API which allowed for custom tax calculations during checkout. This is no longer available to most app developers.
Hi, Did you get any idea to calculate the taxes through custom application?
I am having the same requirement to calculate the taxes on checkout page.
I am not seeing any api to calculate the taxes.
In Notification (Webhook), Tax Service Creation/Update event is available but it's throwing error (Topic Invalid topic specified: tax_services/create.) while clicking on Save Webhook button.
Thanks in Advance!
No, I didn't get anywhere with this. I only found vague rumors that there used to be some sort of API that app developers could use but it seems to have disappeared long ago.
I didn't notice the webhook you mentioned. I guess it's in the admin UI. I can't find anything listed here https://shopify.dev/docs/admin-api/rest/reference/events/webhook?api[version]=2020-04.
I am actively trying to get access this this Tax Services API which was available and does solve the issue you are also trying to solve. There are a number of posts to this forum about the need for editing the tax information at checkout due to inaccuracies in the default tax rates and client needs to have more granular tax rates at jurisdiction level.
To share what I found from dozens of hours of searching, support calls and emails, Shopify has definitely locked down their Tax Services API a couple years ago when they went into contract with Avalara and there is a commercial agreement to use Avalara's tax engine for Shopify Plus merchants through AvaTax app.
No other app exists on Shopify that can interact with the Shopify tax calculation for checkout.
The problem is that AvaTax and Avalara do not always have the correct tax rates and Shopify should look at allowing alternative tax solutions. For example in the state of Colorado, there are over 700 individual tax rates depending on each jurisdictions local rules. AvaTax does NOT get these taxes right and this causes issues with merchants who interact with the State of Colorado.
The state of Colorado recently adopted the Tax Engine of TTR as the source of truth for the entire state.
Any company that uses TTR is "held harmless" by the state of Colorado. Shopify should allow TTR tax engine to be used by anyone doing business in Colorado.
I am trying to build an app for a client using TTR's tax engine and would like help from Shopify so merchants can get accurate tax rates for Colorado and other areas.
I am replying to your message related to the Tax API. We're running into the same issue, specially with AvaTax, inaccuracies and service levels for certain types of compliance. We have the ability to build and integrate our own tax engine if we could have access to the tax API. Have you had any success or have heard anything else in your search?