How to ignore address validation error in Magento 2?

You can ignore address validation for shipping and billing address when you create address programmatically or sometimes you don’t need to worry about validation for billing or shipping address.

Make sure addresses will be saved without validation errors, You need to use setShouldIgnoreValidation(true) function on quote object.

You need to create a quote object first before saving Address,

/**
 * @var \Magento\Quote\Model\Quote
 */
protected $quote;

Create quote Object and assigned as below way,

For Billing address,
$this->quote->getBillingAddress()->setShouldIgnoreValidation(true);

For Shipping address,
$this->quote->getShippingAddress()->setShouldIgnoreValidation(true);